Print in place book press for small books

This is designed to fit on the bed of a Creality K1 - 220 x 220, lying on it's back. It has fairly large (~1mm-2mm, depending on the location) clearances built in due to my struggles calibrating my printer, and unfortunately requires a decent amount of supports. However, once those are removed - it works fairly well.

The screw & nut are shaped weirdly in order to avoid supports being needed within the threads - they should only be needed on the flat surfaces at the bottom of the nut & screw, and potentially to hold up the slits along the walls.

I printed mine out of PETG, with 0.2mm layer heights and organic supports. Since my printer isn't super well calibrated, I had a lot of cleanup along the bottom of the model (the first layer of the bridged sections or above the supports was very stringy and didn't hold it's shape). This was printed with 10% Adaptive Cubic infill & 5 shells (vertical, top and bottom).

This is my first print-in-place device, so any feedback on how it could be improved would be appreciated, though I'm unlikely to apply those changes unless this version has unforeseen issues in use.