I seriously doubt that would hold up in court. If you can convert it back within 10 seconds, can you honestly argue that it isn’t “readily convertible?” No, you can’t. These folks just haven’t been caught. Yet.In fairness to the OP, a lot of dealers will just put a plastic piece in the mag to block it to 10 rds that is easily removed in about 10 seconds. No epoxy, no glue. Nothing. I have't heard of any repercussions doing it this way so far...
The penalty if convicted is becoming a federally prohibited person. Is it worth running that risk to avoid buying some factory 10 round magazines?
Yes, there are a lot folks who break this law. I’ve seen more than a few folks running MBX magazines. If you are comfortable running that risk, then have at it. But don’t whine if you get caught, because you knew the risk you were taking.