There are some problems with RB rewriter in some cases. For example it's hard to rewrite the sender of one message inside a cascaded messages because it entails changing some surrounding nodes to be a correct transformation. There are other cases like that that don't do what one expects. I can have a look to fix these cases, but I'm afraid to break many tools relying on the current behavior of the rewriter :)
improve it and we will check the side effects :)
But if I can succeed doing that, I can keep using RB rewriter of course.
