One down side to the longer whammy bar on the GH:WT controller is that it is even more likely to rotate down under its own weight. This is not a big problem as you can pull it back up when you need it. However, if you play left handed, it can be a real aggravation as it drifts down onto your strumming hand.
I cut a tiny sliver of bamboo from one of those skewers like the ones you would use to grill shrimp on the barbecue. (Now I'm getting hungry. ) I pushed it into the hole that the whammy bar fits into and it added enough friction to keep the whammy bar in place.
It has to be small or it won't fit. Plus, too much force could split the plastic and destroy the guitar and that would be bad. Little more than a tiny sliver cut using a sharp knife did the job for me. It kept the whammy bar in place for an evening of play.
If you have a better fix for this, share it with us!