It'd be great if you could swipe left and right within the app-filling window, such that there was a "Favorites" tab and an "All Logins" tab.
That's an interesting suggestion - I'll pass that along to our development team. Thanks for the suggestion!
The reason for this is because I use several apps that the 1P in-app filling doesn't work. Therefore, instead of trying to find them in my 300+ logins, I would mark them as favorites such that they're easier to find.
That's a great suggestion @Sinsear. I think you brought up another good point here. It would be nice to be able search through your items using 1Password's in-app filling.