some little fuze's spec to help rockbox developers?

The only precedent I see is on the refurb market, where e200V1’s (rockbox compatible) seem to get snapped up quickly while the V2’s (or dealers who don’t say) take a lot longer.

It’s difficult to judge the potential popularity of Rockbox because last I knew there were no supported models in current production.  By the time RB is all developed and tested, the mfr has moved on.