It would be nice to enable/disable individual binding transforms, even if it was just temporary in the designer popup. A complementary feature to this would be to add the ability to duplicate the transform.

Additionally, if there was a way to determine which binding was active (while preserving disabled bindings) that would be helpful for refactoring bindings (especially refactoring an expression structure). I know you can leave the popup open and toggle between the bindings, but accidents happen. I can't tell you how many times I have accidently closed the popup..

I often find myself copying the binding to a temp property (that I often forget to delete) to preserve the original, but these changes would make debugging/refactoring/experimenting with bindings more fluid.