We had a sew sew lady make them for us in Japan. these tapes were "illegal" as they were slightly raised unlike the issue ones through the PC. But, oddly enough, they passed the inspection when my PX/uniform shop ones didn't arrive in time.
As for transfering from one uniform to another. It depends on how well they were sewn on. Ones I had sewn would require a razor blade to cut the threads, I must admit, my sewing was much better than the trained chimps they had in the base uniform shop. And on time as well. And I would easily earn 100 a weekend before and after inspections just sewing the tapes and chevrons on.
If the person sewing used cheap thread, didn't tie the threads down or was sloppy or used minimal stitching per inch then they could easily come off. I saw many a home sew job that was crap. But, the ones I did, no complaints ever, and I never got gigged either
Bottom line, 5 minutes to remove, half hour to do the top. This is by hand and without a machine.