1) The previous format on One UI 2.5 and before was better. Now it is not possible to seamlessly multitask/open different apps and have the top splitscreen app continue to stay open while multitasking. The ″combo″ format on One UI 3 is not as good/useful for productivity.
Can be seen in attached video.
2) When entering splitscreen, the ″Select splitscreen app″ screen is not good for productivity and is a lot more difficult to find the app you want to use. It should open the home screen/previous app (like I believe on previous One UI versions) so you can conveniently open your most used/favourite apps for the lower half of the screen.
3) Relevant error: Splitscreen size adjustments reset when opening a different app then returning to the spitscreen app combo. Can be seen in attached video.
Demonstrating points #1 & #2