So I think what happened is that we released the ability to move fields from the lower to the upper section, but we didnāt have a compact visualisation for all field types, so collections didnāt work.
Then we added the ability to choose how you display fields in different ways.
The combination of these resulted in unlocking what @Marloes described, but we didnāt add much fanfare to that!
Consider it a little Easter egg 