My pre-bamboo design. I wanted to get rid of a hugeass case, but still, have some protection for my steamdeck screen and joysticks while carrying it in a backpack. I didn't want to print with supports or have a complex system with magnets. This is an easier design for a "blast shield" and I believe it will work. It's designed to not touch the screen unless pushed against really hard, in which case it should lock itself in place with gamepad covers.

Options to look out for in this filenames mess:
No case, straight/diagonal
Case from Aliexpress, straight/diagonal
Halves of both, that require spine for rigidity (but you can add spine on top of solid one too)

Used official steamdeck model, expanded horizontal inner part up to 1 extra mm so it can slide in. It makes it a bit wobbly with my printer settings, but with good calibration will work way better. Supposed to be fixed with a rubber band.

You'll need glue, and something to cut down asymmetric parts. Spine is for the middle section in case you'll print in 2 parts. You probably can reduce the tallness of the bottom hook section and make it stick out less. For the bands I use, they are too wide and tall.

Case files is widened design to allow for some solid case I've got from aliexpress (https://www.aliexpress.com/item/1005004768245102.html)

Also feel free to make it more beautiful. I designed it to be useful at first, but beauty aspect would take too much efforts I don't want to put in :-)

Print Settings

Rafts: No

Supports: No

Resolution: 0.2

Infill: 35%, triangles, 2x lines multiplier for rigidity

Filament brand: noname

Filament material: PLA

Notes:

You may want to enable ironing if you don't mind waiting a bit more for smoother parts that might touch the screen. Or just sand paper it down to "smooth enough" state.
Sanding down the center part of the inner shield is advised to reduce chance of scratches when it's pressed against the screen.
Alternatively, you can add some sticker to hold down 2 parts of the print together, and skip gluing down the spine part to make the shield foldable. If sticker will be touching screen, make sure it's wearing protector or brush it off before putting on, because it might rub small particles against the screen and damage it.