The manufacturing tolerances on the OPZ have left a little to be desired in my book. I have a slight bulge in the backplate of my unit. I’ve heard that this flexibility in the back plate was to allow for any manufacturing tolerance issues with the OP-Lab modules, but its still slightly disappointing at that price point. Your issue seems incredibly frustrating, but maybe you could correct it with another wire, as you mentioned.
A friend of mine and I were talking about realized that the next modules could allow for 4 1/8 audio jacks, both in and out to allow for a wider range of audio in/out and sampling options. I had not realized how much I would adore a line in port (or multiple line in’s) until my friend had his a-ha moment. And yea, I get the feeling that this is probably already been a forgone conclusion by many. Hahaha.