As the first step we can try if adding Q_TRACE to QtQuick3D QML profiler tracing points gives us enough data to be even nearly as useful as the current QML profiling.

Check what the data captured with the Q_TRACE traces looks like on Chrome Trace Viewer in Qt Creator (ctf2ctf conversion needed) and Trace Compass.

Q_TRACE produces CTF already on Linux (via LTTng), so the investigation should be done on Linux.