I'm a manufacturing engineer and sometimes fix little things that come up with frames, wheels and boots. The SS bearing inserts may spin in the Xenan frames after repetitive use. These are not threaded in or even pressed in. They are glued in. I've fixed this problem by drilling a small hole on the edge of the insert and tapping it for a 4-40 thread. I place a small set screw in this with red loctite and it prevents it from turning when tightening/loosening the axle.
This is a hole that is drilled through the frame, but catches just a small amount of the insert. The set screw does not stick out to interfere with wheel rotation. Four set screws per side, eight per frame, sixteen total all made of SS. If you know of any skaters who need this fix, I can offer to fix the frames if they are willing to pay for it.
Shipping, parts, and labor I've charged my friends food/drinks for. I'll charge $20 for the fix less shipping charges. I'm not a business, just another speed skater that can help others. Let me know if I can help.