Based on my searches, I could only find 3* controllers that have this feature (and interestingly, they all do it differently). There’s the new 8BitDo Pro 3, where the face buttons are magnetic, the GameSir Supernova, where you have to remove the faceplate to swap the buttons, and the GameSir Tarantula Pro/T3 Pro, where there’s a motor that swaps the ABXY layout.
This seems like a pretty simple feature that would be really useful for multiplatform controllers. Lots of controllers advertise that they work with PC, Xbox, Switch, Android, etc., but very few of them give you the option to physically swap the ABXY layout. They usually have one layout or the other. I would get not having these features on a really budget controller, but there are some controllers that are really expensive and don’t have this neat little button swap thing (instead opting for gimmicky things like a screen)
edit: * There’s actually 4**, I forgot about the Nyxi Flexi!
edit 2: ** Nope, it’s five***, the Gulikit KK3 Max has replaceable button caps! Very cool!
edit 3: *** Actually, the older KK2 Pro also seems to have this feature too, as well as a few other older Gulikit controllers, so I guess it’s >6? That’s cool. With four different companies (GuliKit, 8BitDo, GameSir, and Nyxi) offering at least one controller with this feature, I guess it’s not as rare as I thought. Who knew?
I’m still at a total loss as to the purpose.
The button positions never move, only the letters or colours. You don’t look at your hands when you’re playing, so I don’t get why you’d need to swap buttons at all, outside of a game menu.
If you’re used to blue being left or X being bottom or whatever, do that in the menu. Your thumbs can’t see the buttons so it makes no difference. You have bought a controller to do what a menu does for free at the click of a button (a button that means whatever you assign it to mean).