Sadly, a few years ago I was overruled by the decision that modifications of a single property should also modify the property list it is part of with the standard Modified() event. This bits back in cases like the Properties View and there is no feasible solution for it under these circumstances. The issue is that modifying a property value in the tree view itself now indirectly modifies the whole property list which must trigger a model reset. A workaround is to always expand everything instead of collapse everything, as it won't fight against most of the users intents regarding nested items. The displayed property list is typically longer now by default but there's a filter widget for that anyway.

I also made initial selections work that were selected before the View was opened and made the selection widget not automatically force-select invisible implementation detail data nodes like "Widgets".