I had the same issue, I used to try to play Switch games on the couch and the thinness of the device just made me hold it in a way that would cut off bloodflow, Steam Deck I can seemingly play for hours if I put a pillow in my lap.

I have the JSAUX modcase and I really like it’s grippy texture, not to mention built-in kickstand, and includes a travel cover also generally cheaper than the killswitch

This wasn’t a feature SteamOS had on release, but it’s something I’ve known how to do for years, something I learned from LAN parties in the mid 2000s, you can basically preseed the common directory with a games files and then copy over the appmanifest_######.acf for that game and restart Steam and Voila game is installed.

I originally wrote a script for doing this using WinFSP proxy that allowed me to map my Steam Deck as network drives on my PC, so I could run a script, it would scan my steam libraries show me what games are installed, then I could select the ones I wanted and it would copy them onto the Steam Deck.

Wasn’t even mad when they added this to SteamOS, much more elegant implementation than the clunky system I setup, even though I spent a fair amount of time figuring it out.

This youtube channel has some really good guides for setting up Emudeck and emulation in general, I personally have had really solid results with RPCS3 emulating PS3 games.

https://www.youtube.com/@ED4T