The problem with testing locking bars at events is time. Tech checking every spinner in the arena is bad enough to get done intime, let alone every robot with a locking bar. The rules are fine as they are, they just need to be used!
I have no issue with some of the lock open devices used in feathers as I can see they are very safe I case if miss fire, however I'm not sure I'd be comfortable doing it on a standard heavyweight incase something knock it and the flipper came down.