I'm with BE, I think. I angle my warp bracket all the way forward so that the warpfeed sits parallel with my forearm at a diagonal angle. Then adjust my hopper so that it sits facing forward again, and the warp hose comes out along the right side without needing any hopper mods (no hose-through, no melting and molding around the hose).
That said, without the warpfeed, the hopper is going to sit at pretty much the same level and the bulk of the warpfeed is not going to be in the way of a user's forearm. SO I don't think it's really going to matter much, except where and at what angle you have your warp hose exiting your warpless hopper. But, for that reason and because different hoppers are shaped differently, and have a feed tube positioned differently on the bottom, even though it may be perfectly fine to have the hopper sit back by the grip, it also may be better to have some flexibility.
I do like the fact that the sample CAD looks to have a clamping bracket kind of like a Kapp drop (I used a modified version of that with my first warpless Halo). That is a better solution than drilling a hole in a piece of 1/8" thick aluminum bar and putting tape or a clamp on the bottom of the hopper.