The bug
Unlike the multiplayer warning, there is no way to remember your choice when opening a world with experimental settings. It keeps asking you the same question every time you open a world, which gets very annoying.
MC-206931
Experimental world settings choice is not remembered
Open
10
(Unassigned)
Confirmed
UI
1.16.4, 20w48a, 1.17.1, 1.18 Pre-release 4, 1.18, 1.19.2, 1.21
Retrieved
Can confirm in lasts versions, like 1.21.5, but I didn’t re tried.