So far, my experience with Mature Metal’s customer service is true to their reputation: outstanding! I had a fairly prompt reply from them regarding my serious problems with the security screw. They apologized and said if I can send the device back they will fix it, and provide brand new screws & keys.
Apparently this is the first time they’ve heard of this particular issue, so I guess maybe I just happened to get a “bad” set? Let’s hope that’s all it is. I know I will be testing it very thoroughly by screwing it in and removing it again a ton of times before I actually wear it again! It still kind of scares me a little bit to think about what may have happened if the screw had gotten stuck to this extent while I had the device on!