Tablet Stabilizing Wedge
It's a really simple design that has been an absolute relief for me. My daily driver is a Lenovo Tab P12 with case and keyboard, but the case does not lie flat. The case has two prodtruding stylus retaining prongs. The tablet rocks left and right which makes drawing impossible. It's just a simple wedge with the corners nicked so it wouldn't catch on anything.
The dimensions are 10" long, 2.25" wide, and 0.2" tall. Resizing to fit your needs shouldn't give you any trouble.
The height of the wedge just barely clears the prongs and stylus which is perfect. Print orientation matters a great deal, I printed this 90 degree vertically so that the layer lines would be smoother. Having layer lines on the bottom also helps adhere to the double sided sticky tape (which you'll end up using a lot of). There is a risk of the part falling over mid print, especially when the build plate moves along the Y axis. Printing with a brim and maybe a few supports should help with that.
I thought about printing this in TPU to help with tablet slipping around on the table, but decided against it. I printed it using PLA+, but honestly any material will do. Infill doesn't really matter all that much, but I went with 40% which seems sturdy enough.