Made this quickfix to use the model with nuts instead of threaded inserts. The holes are smaller to get a nice fit with M3 screws. Not easy to hold the nuts in place while tightening the screws but it worked.
I'd suggest to print this with a brim or slow as the original designer stated. The clip part failed on my first print.
The author remixed this model.
Holes for M3 screws to be tightened with nuts.