Did you ever manage to route your dropper internally? I would like to do the same thing. Convert the bike to 1x so that I can get rid of the FD, and then use this entry port on the right had side of the frame for the dropper, take the cable/housing down the down tube, passed the BB should not be a problem, up the seat tube might be a bit more tricky to get it passed the main rocker pivot. Any advice?