The code in my previous post works in some cases but additional conditions must also be met. I eliminated crashes, I think, in Qt 6.1.2 with the following:
A buffer to prevent deletion of the View3D in the code above is required.
The parent hierarchy of the View3D must not have a null parent. Creating an Item with a null parent, adding a View3D, and then settings the item's parent can lead to a crash.
Visibility is important. If adding a View3D to an Item, it seems best to create/add a View3D when the item becomes visible. I'm also releasing the view when the item becomes invisible. This seems to keep Qt happy and so far the crashes are gone.
