I haven't checked (and don't have time for it right now) but is the backend code somehow open source?
Would it be possible for someone who has a full node to run a mycelium backend for himself (and maybe some friends?)
I suppose there are trust issues, so connecting Mycelium to any random backend server might be not advisable, but for personal use it should be ok, and maybe some other trusted organizations would be willing to run Mycelium backends as well.

Onkel Paul