I am confused about this Collections feature. As I read the description it seems to indicate movies will be foldered like TV shows if they’re multi-part films. That should mean Back to the Future 1,2,&3 would be housed in one. However, 5.1 doesn’t seem to be doing that for me. Am I misunderstanding this feature?

Correct - however this feature is only available when browsing via the Library.

Got it! That makes sense now? Quick question about the Library. Can I do a custom logo for that tile?

Not for the title…but you can for any favorites created from the Library (long press on a category to create a favorite).

You can also set custom artwork for these favorites (long-press and choose ‘Select Artwork’).

Opened a feature request for some more options in regard to Collections;
It would open up a lot of possibilities in regard to a bit more themed options as well. But in general my idea was to look into both custom collections and multi-level collections.