Sorry Mo, the FB discussion is on a personal thread so not open. I believe it was discussed in the Double Progress group as well. There was talking of starting a discussion on eCeilidh

The best practical for dance seems to be using an induction loop if there is one, fed from the sound desk if possible. I would look at a seperate mix for the loop, especially for ceilidh where there may be loud acoustic instruments that are low or missing in the FOH mix.

Staghe Electrics have a page on this where they suggest wifi and a smartphone app is possible. I like that for those that are tech comnpetent. As sound desks are increasingly used with their own wireless access point for tablet control adding an audio channel is a logical step.

Not much I can do about callers who can't use a mic! Or singers for that matter. I can, and do, put the caller in the monitors though, so the band can hear.