Tinker Steps:Launcher: Lutris, Set launch options, Lutris
Control Layout:Switch To Community Layout: C&C Couch
Control Layout Customization:Other
Changed back layouts, some ABXY, etc for personal taste.
At the first run, you must run the game with the following arguments "-win -xres 1280 -yres 800", launch the game once before closing it again. You can now remove the "-win" part. Do all this from Lutris. After this you can run the game from the Deck UI.
In order to play with mods, add "-ui" to arguments. This will launch the window normally associated with inserting the game disc. From this window, click Game Browser, then you will find your installed mods under the Mods tab. Tested successfully with Tiberium Essence.