That is not a B4A "thing" but just the way Android works. Even if Erel decided to implement Forms, that would not change the way Android works...the freedom of forms are great, sure.
at android phone you can switch between Activitys / Forms but only one is active, the others gone pause.
see
B4X:StartActivity CallSub CallSubDelayed
+ erels videos at learn between store and community
it remember me at spiderbasic, its a single webpage but as developer forms are possible inside one view.just the way Android works
joYou don't even need a custom view