Launching a Qt 6.2-based Qt DesignStudio emits: SOFT ASSERT: "hasFpsHandler"

When launching a Qt 6 based Qt Creator, this gets emitted:

SOFT ASSERT: "hasFpsHandler" in file C:\Users\alportal\dev\tqtc-qtc-super\qtcreator\src\plugins\qmldesigner\qmlpreviewplugin\qmlpreviewplugin.cpp, line 89

Besides that, do we still need that intricate way of registering the QmlPreview in the Quick Designer? If I understand correctly, that is a left-over from a time where the plugin was in another, commercial-only repository.