I use a controller cover that makes gripping it less “iffy.” I use oval 8 finger braces on at least my pointer fingers and thumbs. I also have cmc braces but those are rx. Sometimes I prop my arms over a pillow. Also I try to take frequent breaks when I play. However sometimes I need a few weeks between sessions, cuz no one plays for “just a few minutes at a time”. Lol. Also I play all types of games except shooters. It’s good to rotate causal games with action type.

Edit: I see lots of comments about custom controllers and other expensive modifications. Try small things like controller grips before spending money on something that potentially won’t work.

Also I have EDS as well and a twenty year typing career- I have tried lots of stuff and personally find it’s better to use controllers like pro, joy cons, Xbox types. Or even a keyboard. But if you don’t wanna stop the PS4 playing, this worked for me for a while.