I’m not a gamer, but i thought it would be a good idea to at least keep a few games “in hand”, just in case. Emulation works great on the uConsole with CM4, up to PSP everything is smooth. But still - many games are unplayable, just because the lack of shoulder (L+R) buttons.
I was thinking of soldering two small buttons on the backplate but maybe there is another, better and less intrusive idea around? How do you “emulate” shoulder buttons? or do you have a workaround?
I actually was thinking about the same thing yesterday. It crossed my mind to add somehow l+r and l2+r2 and even maybe a couple joysticks. Shouldn’t be difficult, but same as you, should think first how to do it without destroying everything lmao
at the moment i’m thinking of simply connecting some small buttons on the GPIO pins on the M2 connector (or directly to the 40pin gpio connector) and writing a small DTOverlay (like on Setting up a GPIO-Button „keyboard“ on a Raspberry Pi – Subjektive Wahrnehmung) - but well, it would require at least two holes in the aluminium backplate.
I use a small bluetooth controller. Yes, its another device to carry. But it is a very good game controller not just for shoulder buttons but all game controls. (8Bitdo SN30 ). Plus I am not so good with making holes in hardware - it often turns out super ugly and I prefer to keep my uConsole stay clean 
the problem with an external controller is, that you cant hold both devices at the same time (unless you are Goro from Mortal Kombat).
Right now i’m thinking of something like this: 1x4 Matrix 4 Tasten Membranschalter Tastenfeld 1*4 Matrix Array Tastatur | eBay with pullup resistors to gpio. but i dont think a foil keyboard is a really good idea…
What I had in mind was more of a “uConsole module”. Some 3D printing and such. I’ll see if I can make a fast sketch after.
