Perhaps you could feed the hose down the seat tube, out the BB shell
Then push the cable/hose and connector into the downtube hole and out of the shell
Both cables now exit on the same side of the bike – take then a decent distance out and use the connector or just some tape. The long distance will allow a smooth bend as you feed the hose into the BB and out of the frame. I don’t think it’d be too bad – not far off what I did on my 2012 Mega, except my hose exits the frame and comes up the outside of the downtube.
The newer Stealths come with a connector at the base – to remove the post, undo the remote, pull the slack into the frame and pull the post out. Undo connector and remove.
It’s a bit more fiddly than a standard Reverb, but I really like the clean routing and extra drop of a 150.