Simplest way I think is saving the controller layout as a template and then you should be available to see in all games when you go to templates.
I do this for the Steam Controller where I saved a general template to use across games so I don't need to reconfigure every single part from scratch.
I wish they made it easier to find games that support simultaneous mouse and game pad inputs, since I like to map mouse to gyro and ideally get analog joystick movement over having to map movement to WASD. And better if they put down whether the game supports locked glyphs so it isn't switching between keyboard and gamepad icons due to detecting mouse and gamepad commands.
Steam Input for use with my steam controller and playstation controller for gyro controls. Particularly love the dual touchpads for movement and camera controls and extra click inputs over a single joystick click. I can't deal with default control schemes anymore when it comes to controllers after becoming reliant on the amount of customization Steam Input provides, since it goes beyond a simple remapping with layers, modeshifts, chords, touch menus, action sets, etc.
Linux support that reduces need to fiddle around with settings and mess with lutris type tools and more devs putting in the time to try to be Steam Deck certified. Even when it doesn't run well on the Deck for more demanding titles there is still benefit for more powerful systems and future Steam Deck follow up.
Existence of Steam forums and guides has come in useful for help and has popped up on search results that I wasn't able to find on pcgamingwiki, so reddit isn't the main place I need to rely on. Been a way to also try to reach devs without having to use reddit or twitter.
Steam workshop. I do use nexusmods, moddb, etc. But, sometimes just having it integrated into Steam makes it convenient.
Other launchers are more like comparing a dumbphone versus a smartphone where if all someone wants to do is make calls and text that is fine, but for those that have become accustomed to Steam launcher features beyond launching games there needs to be more done by competitors. Having to use stuff like GLOSSI to try and utilize Steam Input when using third party launchers, or have to fall back to syncthing to try and sync saves from other launchers when using Steam Deck just makes the lack of Linux and custom controller support apparent.
Seems emulation is the only fall back then if a PC port never comes out to use gyro.
Square because trackpads have always been that way my dude and can be set to a ratio similar to common screen sizes.
I use the Steam Controller and play with dual pads and I have to say I much prefer the circular pads, since the way I set it up is so that a full swipe of the touchpad results in a 180 degree turn in every game I use with mouse input. And circle has been better at providing a more consistent 180 output on swipes over a square where the it can result in varying lengths of travel depending on the angle you enter in at. Square leads to more room for error for the consistent predictable output I want from touchpad use. I don't use stuff like acceleration, so consistency is really what I value.
And I also prefer circle for movement too. I'm not trying to replicate a square display experience when I'm using the touchpads. I really prefer circle for movement and for twin stick shooters over a square surface to rotate around when at the edge.
The square trackpads that have always been that way have been for people using it for slow desktop navigation as opposed to games.
Looks like there isn't one yet even though there is for Steam Deck and Switch. Gulikit did say they want to make some for the dualsense edge first before the dualsense on twitter.
Did you end up fixing it yourself with hall sensor joysticks?
Me neither. I'd get the new one right away. And it's a PC so I can retire my Steam Deck to use to do for other things by then. It's a really great machine.
I think setting up gyro in that case would work better than the touch screen. That's how I played through Maro Galaxy back in the day using the Steam Controller and having gyro only activate when I touched the right pad so it wasn't always going crazy.
I've been playing Diablo IV too. First non Steam game I tried on the Deck, and how well it works blows my mind. Used decky to put in custom artwork too so it fits right in with the rest of my games.
I've been playing around with a set up where I use the right touchpad to enter mouse mode and click to attack for times I need to aim. But, rest of the inputs are gamepad. What I'd like to do is have it so when I touch the right pad it modeshifts the right trigger into a left mouse click too. Could do same with action layers, but I'm hoping for a more straight forward and less problematic modeshift option.
Do you encounter the same issue in desktop mode too?
I tried it on my steam deck and was able to apply my custom template to another game in the normal Steam Deck mode so I wonder if maybe the config is corrupted? Maybe make a simple test config template to check out if it applies to other games is worth trying before making your main config from scratch again.