QmlProfilerTool will try to clearEvents() in this case, and that will rightfully (soft) assert on not being in a permissible state to clear the events. Furthermore, eventally the trigger for finalize() will hit (the details rewriter ...), and finalize() will again be called from the wrong state, causing unknown havoc.
It's unclear what to do about this. In principle we'd have to track down and cancel all the processing that's currently going on, but that would be error prone.
The more future proof option is doing away with the separate "processing" step and resolving the details on the fly. That's also not trivial, though.