No, it's not specific to the RetroArch version, overrides don't save the hotkey configuration, it's saved only when saving the whole configuration.
You can try to add an extra configuration line in /opt/retropie/configs/gba/retroarch.cfg with
where X is the button input code for L2 - you can find it from your gamepad autoconfiguration file in /opt/retropie/configs/all/retroarch-joypads/<gamepad.cfg>.
@TedMaul About Wario Land, I played 1 and 2 and the second game is brilliant and by far better. Its a really good top notch Nintendo quality game, which should say a lot (Quality of Seal 👌🏻). Can't say much about the other parts, as I didn't play them. From my brief experience the third one seems to be good too.
I followed your advice and I'm pleased to report that GBA games are now working under the other emulator and they are working really well. No more stutter! Thank you! Finally my GPI can run more than GB games! :D
I've had this problem recently with Legend of Mana for psx. It was the controller type that was set to analog, but the game refused to work until I changed it back to standard and restarted it. Some cores/games are a bit finicky with analog controllers and how they're configured, in my experience. Try messing with that option to see if solves you problem.
Thanks for the reply! I installed Retroarch on my phone to see a bit of what you mean. Fewer shaders are available and the same shaders I use on my PC look different thanks to the phone's much higher PPI, and/or maybe some other factors. I suppose this would mainly apply to people playing on Windows or Linux on a 1080 - 4k screen. If you feel this question is of no use here, feel free to remove it.
Roms are all working on my PC.
I realize it was just a issue during the transfert of the rom to my raspberry, now it should work.... but actually my raspberry pi seems not to respond to my SD card.
I tried to reboot on the new retropie IMG, and nothing. Green led blink twice, then nothing.... when I try the same SD card on another pi It's working.
If you have any advice for this issue, that would be great.
You already helped me a lot. Thank you.