Well most
fixed bridge guitars will stay in tune just as good if not better than a locking tremelo guitar because 90% of the people that use them can't set them up themselves. String gauge shouldn't have anything to do with tuning stability, It could be how you string your guitar though. If you wrap the string around the post too much, thats more string that needs to stretch, getting locking tuners takes care of that because you don't need to do more than a single wrap. I can't really know for sure without having the guitar in my hands, but locking tuners always help stability.
