Unable to Terminate QtWebEngine Before Application Exits

[I'm unclear if this is a bug, a user story, a requested task, or that I just can't find something in the documentation. Thank you for any assistance.]

Context: It is very important for our system to be memory-leak free. We build Qt, linking to mfc to ensure a common heap is used. This allows us to work with the _CRTDBG_MAP_ALLOC/_CrtSetDbgFlag( _CRTDBG_ALLOC_MEM_DF | _CRTDBG_LEAK_CHECK_DF ) calls to detect memory leaking on exit.

We've recently added a QtWebEngineView as a widget to our system, which brings along all the web engine processes and threads. On exit, it appears that these threads aren't shut down, and all memory resources are (erroneously?) reported as leaks. I've read through the documentation, and I'm struggling to find something to "correctly" terminate and release all web engine content prior to exit. A similar issue happens when working just with an OpenGL widget.

Question: How does one correctly terminate and release all resources - including its OpenGL context - associated with qt web engine?

If the motivation is insufficient, another justification would be how to release all web engine resources during program execution, in the case of limited resources?

A simple example program is attached.