Like with the Steam Deck, there are a number of third-party mods out there for the ROG Ally, both cosmetic and functional. Something I've been trying to accomplish with my own ROG Ally is to try and bring down the temperatures a little. Heat is your enemy, and if you can reduce it, in theory, you should be able to squeeze a little more performance out of the thing.
What I've got here is a little bit of a cosmetic glow up as well as, ideally, help with cooling the ROG Ally a little better. I'm not expecting miracles, which is good, because I haven't got them.
