[ascagnel_]

I haven't played XCOM 2, but the 2012 XCOM had controller support. If you have an Xbox One, PS4, or one of the older MFi controllers paired with your iPad, the Steam Link app can pass those controller inputs through to the running game.

Aside from the "drag past the bottom of the screen to go home" issue, I find the mouse support has worked really well in games that have an on-screen cursor (I've tested with SimCity 4, Disco Elysium, and Factorio). It doesn't work at all in games that expect to fully capture the cursor (usually to control a camera perspective, so most first person or action games).