The first thing I did when I got my fates is to make a library for alternative midi grids to do just such a thing. I only have an apc mini, and it works well with that, but I have yet to get anyone to successfully test it with untzes.
But in principal, I don’t see why they shouldnt work. I have the full api for monome grids recreated as midi handlers, that successfully tricks any script that its talking to a grid. Midi data is even parsed and buffered in the same way as grids for performance. You just need to configure it for the midi messages the untz gives and expects.
It works very well for me, I have a $40 dollar 64 grid (or 128 grid in my “2 page” mode) with it seems very little sacrifice (other than I guess aesthetic sacrifice)!
Maybe one day if I ever have money I will do the neotrellis thing, and make a library that fully supports them for norns, but thats still a long way off financially for me! Anyone is welcome to PR my code or steal from it to do such a thing.
EDIT: there is a thread here designated for these discussions Norns: alternative grids