This model can be considered a first prototype of the idea. Although it works well in practice, there are a couple things that can be improved:
I printed the model in the same orientation as it would stand, but the print quality at the top near the opening suffers since it is essentially a tall thin unsupported wall. It may be better to print in the orientation of the STL and use supports.
The angle should probably be more vertical, currently it is 75 degrees.
The case holds together decently due to the alignment features, but a positive lock would be nicer.
The case takes around 500g in PLA, which seems too much. Should experiment with thinner walls, maybe also ABS/ASA which is less dense. Warping would be an issue (it already noticable with PLA).