The other day I was watching Steam's official "tear-down" video on the new Steam Deck handheld PC, and I noticed that the person was using what I could only call a "repair jig" that he had the Deck itself sitting on, so that he could place the deck face down on a table but not have the sticks, buttons or screen directly be on the table, potentially messing up these parts as he took the back cover off.
Here's the video of the tear-down:
https://youtu.be/UahXjChuiPI

So, I imagine that Valve wouldn't make these types of jigs available to just anybody, so I decided to make my own. I took a screenshot of the jig itself and tried to re-model it from scratch as best I could. Hopefully I made it about as accurate as possible, with some space around the buttons and sticks for some leeway.

I would also probably imagine that it would be recommended to perhaps line the top surface of this with maybe a few strips of soft rubber or stick-on felt so that your Steam Deck doesn't lay directly on this.

Also, the size of the Steam Deck itself is rather wide, and I know this couldn't be printed in a single piece on a standard Ender 3 or similarly sized printer, so I did provide a version of the model that is cut in half with some dove-tails built into it.

Note: Apparently mine is a bit off. Check the remixes out as MehStrongBadMeh was kind enough to fix some of the dimensions that I was off by!
https://www.thingiverse.com/thing:5145310