We have not encountered this but I have friends who sign, having been teachers who worked with the deaf. Both dancers. I am going to talk with them about how this could work.
I think signing during the dance would be problematic as the dancer would need to see the signer and that would take their attention away from the dance floor.
The caller surely would find it difficult as well. I used to sign well but lost some over the years; once had a group of deaf tourists ride in my tour carriage, even signing, holding reins and being aware of traffic, tour sites and passengers was hugely difficult.
Having a trained -for- dance interpreter might just work for the walk through and occasional prompting.
Definitely looking into this.
Mary Collins
Near Buffalo NY