Basically we were applying the default values onComponentComplete therefore overriding any user value.

This patch applies the default on creation before properties are set so the user can now override.

src/timeline/timelinedelegate.cpp

@@ -109,9 +109,9 @@ void TimelineDelegate::geometryChange(const QRectF &newGeometry, const QRectF &o
     QQuickItem::geometryChange(newGeometry, oldGeometry);
 }
 
-void TimelineDelegate::componentComplete()
+void TimelineDelegate::classBegin()
 {
-    QQuickItem::componentComplete();
+    QQuickItem::classBegin();
 
     auto engine = qmlEngine(this);
     Q_ASSERT(engine);
@@ -121,6 +121,11 @@ void TimelineDelegate::componentComplete()
     connect(m_units, &Kirigami::Platform::Units::largeSpacingChanged, this, &TimelineDelegate::setCurveValues);
     connect(m_units, &Kirigami::Platform::Units::smallSpacingChanged, this, &TimelineDelegate::setCurveValues);
     setCurveValues();
+}
+
+void TimelineDelegate::componentComplete()
+{
+    QQuickItem::componentComplete();
 
     if (m_isDirty) {
         resizeContent();

src/timeline/timelinedelegate.h

@@ -95,6 +95,7 @@ protected:
     bool m_resizingContent = false;
 
 private:
+    void classBegin() override;
     void componentComplete() override;
     void geometryChange(const QRectF &newGeometry, const QRectF &oldGeometry) override;
     void updatePolish() override;