Nylok type fastener locking designs do have an issue that most here might not consider, they don't like much reuse. As long as the locking insert has rebound ability and can equally recompress on reuse there's no problem with reusing these. But with each assembly the insert does loose some effectiveness. So to over time as the plastic dries out.

Think about a rack install where you might dry fit the rack a couple of times or more (especially if fenders are in play) and using the same nylok nuts. The end fitting could well end up with a significant loss of locking ability. Just one more reason to consider these thread locking things as the suspenders to the belt of good fit up and torque. In my view thread locking is secondary to good fit up, yet I read so much mention of thread locking stuff and so little about assembly alignment. Andy