One thing missing with the new handhelds and designs, and presumably a DIY design, is the dual touchpad on the steamdeck. IMO its what makes the steamdeck so popular even though its underpowered at this point. I was just playing a 2000's era PC game (Dungeon Siege) designed with keyboard and mouse with the steamdeck easily, because of the dual touchpads they integrated. Not sure you can buy those off the shelf and integrate them into a DIY project with drivers etc that easily. But maybe I'm wrong, maybe there's an off the shelf solution for this? If there is thats fucking awesome!