One last tricky question : is there any way to make buses ID from 1 to 8 ? I explain myself : You can "group folders to the left" or do the same with "tracks which have receives". but their ID are still the original one. Result : midi communication with controllers won't show the busses to the left, but they will still show the tracks according to their ID number, from 1 to the last one. Therefore the feature is not usable with a controller because it will then not show the same. So the "group folders to the left" is only a cosmetic/GUI action in Reaper, but I would like it to actually show on a controller. Is there any way to do this as of now ? Of course I can send/receive to tracks manually, which I have done, but if this could be done natively or automatically, that would make my day !