diff --git a/GUI/Model/BaseItem/SessionItem.h b/GUI/Model/BaseItem/SessionItem.h
index 114d989bfa44bfacdacda695dee72d571fbe5fc0..e2abe50a776105c04ca48b35a3e8d6e25eefe891 100644
--- a/GUI/Model/BaseItem/SessionItem.h
+++ b/GUI/Model/BaseItem/SessionItem.h
@@ -201,6 +201,7 @@ class GroupInfo;
 //!
 //! This code part again shows the (highly error-prone) string-based type checking.
 //#define USE_MAPPERS
+#include <QDebug>
 class BA_CORE_API_ SessionItem {
     friend class SessionModel;
 
diff --git a/GUI/Model/Data/DataItem.cpp b/GUI/Model/Data/DataItem.cpp
index 14a00f8e6a2cb530f8877bfbee39bc1b359e1093..df4832af96cffc2292b4cd7986cbb2bd0e4e2a5d 100644
--- a/GUI/Model/Data/DataItem.cpp
+++ b/GUI/Model/Data/DataItem.cpp
@@ -23,7 +23,7 @@ void DataItem::setDatafield(Datafield* data)
     m_data.reset(data);
 
     setLastModified(QDateTime::currentDateTime());
-    emit datafieldChanged(data);
+    emit datafieldChanged();
 #ifdef USE_MAPPERS
     emitDataChanged();
 #endif
diff --git a/GUI/Model/Data/DataItem.h b/GUI/Model/Data/DataItem.h
index a5dda13c826ab1e12646440a59ddf8bee691a2b9..7ad4f7ca37e4db70baf016cedcc22209448000f2 100644
--- a/GUI/Model/Data/DataItem.h
+++ b/GUI/Model/Data/DataItem.h
@@ -76,7 +76,7 @@ public:
     virtual void reset(ImportDataInfo data) = 0;
 
 signals:
-    void datafieldChanged(Datafield* data);
+    void datafieldChanged();
     void rawDataVectorChanged(const std::vector<double>& data);
     void fileNameChanged(const QString& filename);
     void axesUnitsChanged();
diff --git a/GUI/Model/Data/IntensityDataItem.cpp b/GUI/Model/Data/IntensityDataItem.cpp
index 99d4882bb309bd3ce14a66aa553de9b141c712dc..48403c5165ffa97757d5d2ec6f22d39c47ea35a3 100644
--- a/GUI/Model/Data/IntensityDataItem.cpp
+++ b/GUI/Model/Data/IntensityDataItem.cpp
@@ -331,7 +331,7 @@ void IntensityDataItem::setLogz(bool logz)
 void IntensityDataItem::setInterpolated(bool interp)
 {
     setItemValue(P_IS_INTERPOLATED, interp);
-    emit interpolationChanged();
+    emit interpolationChanged(interp);
 }
 
 //! Sets zoom range of X,Y axes, if it was not yet defined.
diff --git a/GUI/Model/Data/IntensityDataItem.h b/GUI/Model/Data/IntensityDataItem.h
index 7b1c329eca053a33b9b38492c5d39cef1b45d9d2..f49cfa755be248349534f6729dd0ca7b7ed40174 100644
--- a/GUI/Model/Data/IntensityDataItem.h
+++ b/GUI/Model/Data/IntensityDataItem.h
@@ -26,6 +26,7 @@ class ProjectionContainerItem;
 class BA_CORE_API_ IntensityDataItem : public DataItem {
     Q_OBJECT
 private:
+//    using DataItem::mapper;
     static constexpr auto P_PROJECTIONS{"Projections"};
     static constexpr auto P_TITLE{"Title"};
     static constexpr auto P_IS_INTERPOLATED{"Interpolation"};
@@ -123,7 +124,7 @@ public:
 
 signals:
     void gradientChanged();
-    void interpolationChanged();
+    void interpolationChanged(bool isInterpol);
     void axesRangeChangedFromPlot();
     void updateOtherPlots();
     void updateThisPlot();
diff --git a/GUI/Model/Device/AxesItems.cpp b/GUI/Model/Device/AxesItems.cpp
index e4845490fc18bb9ee87bd8d1c55d4e04e2484265..3fa213675e93552705392e521f37f1665dd54a24 100644
--- a/GUI/Model/Device/AxesItems.cpp
+++ b/GUI/Model/Device/AxesItems.cpp
@@ -195,7 +195,7 @@ bool AmplitudeAxisItem::isLogScale() const
 void AmplitudeAxisItem::setLogScale(bool value)
 {
     setItemValue(P_IS_LOGSCALE, value);
-    emit logScaleChanged();
+    emit logScaleChanged(value);
 }
 
 SessionItem* AmplitudeAxisItem::logScaleItem() const
diff --git a/GUI/Model/Device/AxesItems.h b/GUI/Model/Device/AxesItems.h
index f17244c1c0b5d2ba1352d75279fb4b30822e9add..cb100e772a544df00639ed3cdd016cea43c9cfa8 100644
--- a/GUI/Model/Device/AxesItems.h
+++ b/GUI/Model/Device/AxesItems.h
@@ -99,7 +99,7 @@ public:
     void setLocked(bool locked);
 
 signals:
-    void logScaleChanged();
+    void logScaleChanged(bool isLog);
 
 };
 
diff --git a/GUI/Model/Model/JobFunctions.cpp b/GUI/Model/Model/JobFunctions.cpp
index fde7b61c058590eda02d56932c55a23af5da08e7..5b122c3f7e1f81d4b68d8bfdef38b5ec73ce2f5f 100644
--- a/GUI/Model/Model/JobFunctions.cpp
+++ b/GUI/Model/Model/JobFunctions.cpp
@@ -112,6 +112,7 @@ void GUI::Model::JobFunctions::initDataView(JobItem* job_item)
     // also triggers Data1DViewItem::setAxesRangeToData and
     // GUI::Model::DataViewUtils::updateAxesTitle by setting new value of P_AXES_UNITS.
     auto* converter = job_item->instrumentItem()->createCoordSystem();
+
     view_item->setAxesUnits(GUI::Model::JobItemUtils::availableUnits(*converter));
 }
 
diff --git a/GUI/Model/Model/JobModel.cpp b/GUI/Model/Model/JobModel.cpp
index fcaede6d5a9f0ad4fcc5349d9e92dd6a40ba476a..782fe82ee69caa2a398a6659e26158afbdfedd4b 100644
--- a/GUI/Model/Model/JobModel.cpp
+++ b/GUI/Model/Model/JobModel.cpp
@@ -55,7 +55,8 @@ JobItem* JobModel::addJob(const MultiLayerItem* sampleItem, const InstrumentItem
     ASSERT(sampleItem);
     ASSERT(instrumentItem);
 
-    auto* jobItem = insertItem<JobItem>();
+    JobItem* jobItem = insertItem<JobItem>();
+    emit jobAdded();
     jobItem->setItemName(generateJobName());
     jobItem->setIdentifier(QUuid::createUuid().toString());
 
diff --git a/GUI/Model/Model/JobModel.h b/GUI/Model/Model/JobModel.h
index 27bcc68fbf2b92f6157be95edd6ce32ee64a4f0c..70877ed61aa7a9d792e83bc1269a75015e470bd0 100644
--- a/GUI/Model/Model/JobModel.h
+++ b/GUI/Model/Model/JobModel.h
@@ -53,6 +53,7 @@ public:
 signals:
     void focusRequest(JobItem* item);
     void globalProgress(int);
+    void jobAdded();
 
 private:
     //! generates numbered job name with new/unused number
diff --git a/GUI/View/Job/JobListModel.cpp b/GUI/View/Job/JobListModel.cpp
index b5af7038faf6449e36592e9e1921c5f50178c332..cdae3c976382d656b5a4e1ee007beb1cde637114 100644
--- a/GUI/View/Job/JobListModel.cpp
+++ b/GUI/View/Job/JobListModel.cpp
@@ -28,19 +28,16 @@ JobListModel::JobListModel(JobModel* jobs, QObject* parent)
     : QAbstractListModel(parent)
     , m_jobs(jobs)
 {
-    for (JobItem* job : m_jobs->jobItems())
+    for (JobItem* job : m_jobs->jobItems()) {
         enableJobNotification(job);
-
-    connect(jobs, &QAbstractItemModel::rowsAboutToBeInserted, this,
-            &JobListModel::onRowsAboutToBeInserted);
-    connect(jobs, &QAbstractItemModel::rowsInserted, this, &JobListModel::onRowsInserted);
+    }
+    connect(jobs, &JobModel::jobAdded, this, &JobListModel::onJobAdded, Qt::UniqueConnection);
 }
 
 JobListModel::~JobListModel()
 {
-    for (JobItem* job : m_jobs->jobItems()) {
+    for (JobItem* job : m_jobs->jobItems())
         disableJobNotification(job);
-    }
 }
 
 int JobListModel::rowCount(const QModelIndex&) const
@@ -111,20 +108,10 @@ void JobListModel::emitJobListModelChanged(JobItem* job)
 // private slots
 //--------------------------------------------------------------------------------------------------
 
-void JobListModel::onRowsAboutToBeInserted(const QModelIndex& parent, int start, int end)
+void JobListModel::onJobAdded()
 {
-    if (!parent.isValid())
-        beginInsertRows(QModelIndex(), start, end);
-}
-
-void JobListModel::onRowsInserted(const QModelIndex& parent, int start, int end)
-{
-    if (!parent.isValid()) {
-        endInsertRows();
-        QVector<JobItem*> jobs = m_jobs->jobItems();
-        for (int i = start; i <= end; i++)
-            enableJobNotification(jobs.at(i));
-    }
+    for (JobItem* job : m_jobs->jobItems())
+        enableJobNotification(job);
 }
 
 //--------------------------------------------------------------------------------------------------
@@ -134,15 +121,13 @@ void JobListModel::onRowsInserted(const QModelIndex& parent, int start, int end)
 void JobListModel::enableJobNotification(JobItem* job)
 {
     // name
-    connect(job, &JobItem::jobNameChanged, this,
-            [=](const QString&) { emitJobListModelChanged(job); });
+    connect(job, &JobItem::jobNameChanged, this, [=]() { emitJobListModelChanged(job); });
 
     // status
-    connect(job, &JobItem::jobStatusChanged, this,
-            [=](const JobStatus) { emitJobListModelChanged(job); });
+    connect(job, &JobItem::jobStatusChanged, this, [=]() { emitJobListModelChanged(job); });
 
     // progress
-    connect(job, &JobItem::jobProgressChanged, this, [=](int) { emitJobListModelChanged(job); });
+    connect(job, &JobItem::jobProgressChanged, this, [=]() { emitJobListModelChanged(job); });
 }
 
 void JobListModel::disableJobNotification(JobItem* job)
diff --git a/GUI/View/Job/JobListModel.h b/GUI/View/Job/JobListModel.h
index 202ab4203d2f830a8c54d44a86fd6dab3d1bd9bd..19cedddd7435a1070608988a2821362a987027f7 100644
--- a/GUI/View/Job/JobListModel.h
+++ b/GUI/View/Job/JobListModel.h
@@ -40,8 +40,7 @@ public:
 
 private slots:
     void emitJobListModelChanged(JobItem* job);
-    void onRowsAboutToBeInserted(const QModelIndex& parent, int start, int end);
-    void onRowsInserted(const QModelIndex& parent, int start, int end);
+    void onJobAdded();
 
 private:
     void enableJobNotification(JobItem* job);
diff --git a/GUI/View/PlotComparison/FitComparisonController.cpp b/GUI/View/PlotComparison/FitComparisonController.cpp
index 3a23142b7e2eec12fabdc7ef19bc71b6f1731f04..748850d1ec4903b5fe030bf3020ac3e9e81317bf 100644
--- a/GUI/View/PlotComparison/FitComparisonController.cpp
+++ b/GUI/View/PlotComparison/FitComparisonController.cpp
@@ -177,7 +177,7 @@ void DiffItemController::subscribe()
     m_current_item->dataItem()->mapper()->setOnValueChange([this]() { updateDiffData(); }, this);
 #else
     connect(m_current_item->dataItem(), &DataItem::datafieldChanged, this,
-            [=](Datafield*) { updateDiffData(); });
+            &DiffItemController::updateDiffData, Qt::UniqueConnection);
 #endif
 
     // on diff item units change
diff --git a/GUI/View/PlotComparison/FitComparisonViewController.cpp b/GUI/View/PlotComparison/FitComparisonViewController.cpp
index c865c740a37a26e84381d3915afc2458bc6ba921..edcf973169040d651aa6c5b8fc606079f20f9955 100644
--- a/GUI/View/PlotComparison/FitComparisonViewController.cpp
+++ b/GUI/View/PlotComparison/FitComparisonViewController.cpp
@@ -168,23 +168,20 @@ void DiffItemController::subscribe()
     m_current_item->dataItem()->mapper()->setOnValueChange([this]() { updateDiffData(); }, this);
 #else
     connect(m_current_item->dataItem(), &DataItem::datafieldChanged, this,
-            [=](Datafield*) { updateDiffData(); });
+            &DiffItemController::updateDiffData, Qt::UniqueConnection);
 #endif
 }
 
 void DiffItemController::unsubscribe()
 {
-#ifdef USE_MAPPERS
-    m_diff_item->mapper()->unsubscribe(this);
-#else
-    disconnect(m_diff_item, nullptr, this, nullptr);
-#endif
     if (!m_current_item)
         return;
 #ifdef USE_MAPPERS
     m_current_item->dataItem()->mapper()->unsubscribe(this);
+    m_diff_item->mapper()->unsubscribe(this);
 #else
     disconnect(m_current_item->dataItem(), nullptr, this, nullptr);
+    disconnect(m_diff_item, nullptr, this, nullptr);
 #endif
     m_current_item = nullptr;
 }
diff --git a/GUI/View/PlotComparison/Plot1D.cpp b/GUI/View/PlotComparison/Plot1D.cpp
index c7d9acb45ecc9d906374d0bcf80781ad5789f9db..834b7751639c01043f4c85607a208b366bbd2686 100644
--- a/GUI/View/PlotComparison/Plot1D.cpp
+++ b/GUI/View/PlotComparison/Plot1D.cpp
@@ -134,7 +134,7 @@ void Plot1D::subscribeToItem()
 #else
         DataItem* dataItem = pair.first->dataItem();
         connect(dataItem, &DataItem::datafieldChanged, caller,
-                [caller](Datafield*) { caller->refreshPlotData(); });
+                [caller]() { caller->refreshPlotData(); });
 #endif
     });
     setConnected(true);
diff --git a/GUI/View/PlotUtil/ColorMap.cpp b/GUI/View/PlotUtil/ColorMap.cpp
index afe6b6f7e16fd9dac0abfa5dd55064a5892c8628..9393941ec03c92702c8315c5161cd365b7b7bd5b 100644
--- a/GUI/View/PlotUtil/ColorMap.cpp
+++ b/GUI/View/PlotUtil/ColorMap.cpp
@@ -225,9 +225,8 @@ void ColorMap::subscribeToItem()
     intensityItem()->mapper()->setOnValueChange([this]() { onIntensityModified(); }, this);
 #else
     // datafield
-    connect(intensityItem(), &IntensityDataItem::datafieldChanged, this, [=]() {
-            onIntensityModified();
-    });
+    connect(intensityItem(), &IntensityDataItem::datafieldChanged, this,
+            &ColorMap::onIntensityModified, Qt::UniqueConnection);
     // units
     connect(intensityItem(), &IntensityDataItem::axesUnitsReplotRequested, this, [=]() {
             setAxesRangeFromItem(intensityItem());
diff --git a/GUI/View/PlotUtil/IntensityDataPropertyWidget.cpp b/GUI/View/PlotUtil/IntensityDataPropertyWidget.cpp
index 53ca1596d924f4926d4e95784498f985eef14786..34c30ba65ad4c2614edfe4903cbc24d8cdd1aaad 100644
--- a/GUI/View/PlotUtil/IntensityDataPropertyWidget.cpp
+++ b/GUI/View/PlotUtil/IntensityDataPropertyWidget.cpp
@@ -28,7 +28,7 @@
 #include <QLineEdit>
 
 #define FOR_EACH_ITEM                                                           \
-    for(IntensityDataItem* item : m_items_vec)                                  \
+    for(IntensityDataItem*& item : m_items_vec)                                 \
         if(item)
 
 IntensityDataPropertyWidget::IntensityDataPropertyWidget(QWidget* parent)
@@ -141,14 +141,12 @@ void IntensityDataPropertyWidget::setItem(QVector<IntensityDataItem*> itemsVec)
 
     updateUIValues();
 
-    // react on external changes (e.g. zooming in customplot shall update the axis values)
-
-
-    // update coordinates on axes units change
 #ifdef USE_MAPPERS
+    // react on external changes (e.g. zooming in customplot shall update the axis values)
     first_item->mapper()->setOnChildPropertyChange(
                 [=](SessionItem*, const QString&) { updateUIValues(); }, this);
 
+    // update coordinates on axes units change
     first_item->mapper()->setOnPropertyChange(
                 [this](SessionItem* item, const QString& name) {
         if(jobItem())
@@ -160,7 +158,7 @@ void IntensityDataPropertyWidget::setItem(QVector<IntensityDataItem*> itemsVec)
                         [&](SessionItem*) { item = nullptr; }, this);
 
 #else
-    // update values on panel
+    // react on external changes (e.g. zooming in customplot shall update the axis values)
     FOR_EACH_ITEM
             connect(item, &IntensityDataItem::axesRangeChangedFromPlot, this, [=](){
                 updateUIValues();
diff --git a/GUI/View/Projection/ProjectionsEditor.cpp b/GUI/View/Projection/ProjectionsEditor.cpp
index e8cb68749eadaf12551d7397f460f73fb8f349f4..6e93d5b5c1871b0ae7ca8d4ab74d2b2da693a78f 100644
--- a/GUI/View/Projection/ProjectionsEditor.cpp
+++ b/GUI/View/Projection/ProjectionsEditor.cpp
@@ -101,7 +101,10 @@ JobItem* ProjectionsEditor::jobItem()
 
 IntensityDataItem* ProjectionsEditor::simulatedIntensity()
 {
-    return dynamic_cast<IntensityDataItem*>(jobItem()->dataItem());
+    if(jobItem())
+        return dynamic_cast<IntensityDataItem*>(jobItem()->dataItem());
+    else
+        return nullptr;
 }
 
 IntensityDataItem* ProjectionsEditor::realIntensityDataItem()
diff --git a/GUI/View/Projection/ProjectionsPlot.cpp b/GUI/View/Projection/ProjectionsPlot.cpp
index 810cc383afaaea9a1560d5fbead99cc455fd262b..ad6524a68580a6fccd284f094b374d57b2a47120 100644
--- a/GUI/View/Projection/ProjectionsPlot.cpp
+++ b/GUI/View/Projection/ProjectionsPlot.cpp
@@ -81,25 +81,63 @@ void ProjectionsPlot::subscribeToItem()
         this);
 
     // Values of intensity changed, regenerate everything.
-    intensityItem()->mapper()->setOnValueChange(
-        [this]() {
+#ifdef USE_MAPPERS
+//    intensityItem()->mapper()->setOnValueChange(
+//        [this]() {
+//            updateProjectionsData();
+//            updateProjections();
+//        },
+//        this);
+#else
+    connect(intensityItem(), &IntensityDataItem::datafieldChanged, this, [=]() {
             updateProjectionsData();
             updateProjections();
-        },
-        this);
+    });
+#endif
 
-    // IntensityItem property (e.g. interpolation changed)
+    // interpolation changed
+#ifdef USE_MAPPERS
     intensityItem()->mapper()->setOnPropertyChange(
         [this](const QString& name) { onIntensityItemPropertyChanged(name); }, this);
+#else
+    connect(intensityItem(), &IntensityDataItem::interpolationChanged, this,
+            &ProjectionsPlot::setInterpolate, Qt::UniqueConnection);
+#endif
 
-    // Update to changed IntensityDataItem axes
+    // AXES
+#ifdef USE_MAPPERS
     intensityItem()->mapper()->setOnChildPropertyChange(
         [this](SessionItem* item, const QString name) {
             if (item->modelType() == BasicAxisItem::M_TYPE
-                || item->modelType() == AmplitudeAxisItem::M_TYPE)
+                || item->modelType() == AmplitudeAxisItem::M_TYPE) {
                 onAxisPropertyChanged(item->itemName(), name);
+            }
         },
         this);
+#else
+    // if the colormap is zoomed or dragged:
+    connect(intensityItem(), &IntensityDataItem::updateOtherPlots, this,
+            &ProjectionsPlot::updateAxesRange, Qt::UniqueConnection);
+
+    // if axes are changed externally, from the properties panel:
+    // axes range
+    connect(intensityItem()->xAxisItem(), &BasicAxisItem::axisRangeChanged, this,
+            &ProjectionsPlot::updateAxesRange, Qt::UniqueConnection);
+    connect(intensityItem()->yAxisItem(), &BasicAxisItem::axisRangeChanged, this,
+            &ProjectionsPlot::updateAxesRange, Qt::UniqueConnection);
+    connect(intensityItem()->zAxisItem(), &BasicAxisItem::axisRangeChanged, this,
+            &ProjectionsPlot::updateAxesRange, Qt::UniqueConnection);
+
+    // axes title
+    connect(intensityItem()->xAxisItem(), &BasicAxisItem::axisTitleChanged, this,
+            &ProjectionsPlot::updateAxesTitle, Qt::UniqueConnection);
+    connect(intensityItem()->yAxisItem(), &BasicAxisItem::axisTitleChanged, this,
+            &ProjectionsPlot::updateAxesTitle, Qt::UniqueConnection);
+
+    // z log scale
+    connect(intensityItem()->zAxisItem(), &AmplitudeAxisItem::logScaleChanged, this,
+            &ProjectionsPlot::setLogz, Qt::UniqueConnection);
+#endif
 
     updateProjectionsData();
     updateProjections();
diff --git a/GUI/View/Toplevel/SimulationView.cpp b/GUI/View/Toplevel/SimulationView.cpp
index 3d0879fd33554804b526167e4a653ca81c467c95..bca752e6bb46d5c660ee5311e5aea82920527515 100644
--- a/GUI/View/Toplevel/SimulationView.cpp
+++ b/GUI/View/Toplevel/SimulationView.cpp
@@ -194,7 +194,8 @@ void SimulationView::updateSelection(QComboBox* comboBox, QStringList itemList,
     }
 
     if (allowNone)
-        itemList.insert(-1, "None");
+        itemList.prepend("None");
+
     comboBox->addItems(itemList);
     if (itemList.contains(previousItem))
         comboBox->setCurrentIndex(itemList.indexOf(previousItem));