Jake, I'm not seeing any pictures. Sounds like you have already run your cables but for the sake of completeness I'll ask a few more questions. For the brake line, did you try starting at the chain stay and pushing the line up to the top tube? For the R/D, I would expect you should have cable housing from the lever to the frame, bare cable run inside the liner to the exit point in the chain stay, then housing from the chain stay to the R/D mech. Looks like the IP-256 also has an access cover on the underside of the BB to help with cable routing, under the plate is some cable routing guides and from what I've seen those guides are sized for bare cable.
I continue to be curious as to why causing the cable routing on your IP-256 to be difficult.
I haven't done the brake line yet. I am planning to do it tomorrow, I am just making up my mind how to do it....
Yes I am planning to start at the chainstay.. I still have to figure out how to use the sleeve as a pullwire.
The R/D is in, it is the bare cable in this picture, the sleeve you can see is waiting for my future dropper's cable
The cable routing on the 256 is not difficult!
I am just going slow because I don't want to make any stupid mistakes...and I am injured which will hopefully not last more than another week.