The old (Qt4) QFileDialog used to add the current folder to the list of folders in the sidebar URL. After migrating to Qt5, this no longer works. I hacked a workaround to show the usual entries in the sidebar, but adding a custom one no longer works.
If you know Qt5, could you help out?
See the issue with more info (it’s closed but don’t let that bother you):
Personally, I prefer the native dialog, though I haven’t had firsthand experience with it. In any case, I typically copy-paste the path I need so it doesn’t affect me.