That might be quite a nice little feature at some point, but I'm unconvinced as to it's actual necessity. It'd certainly make a fun thing to play with, but you're the first person who's ever found that the available ranger curves are not enough for their needs - all our in house players tested them and were quite happy with the available options as far as manipulating pitchbend curves go. Was there a specific thing that you wanted to do with the curves that's not covered by the ones we ship? Adding a graphical tool is a lot of work for something that we've not had any other requests for so it's not likely to happen in the near term, but if you have specific want that makes sense then we could probably add some other curves to the the set to help out. Let us know.