FFF
Presumably, if you're training for an IMC rating, you have an aircraft availabe which is equipped for flight in IMC? Otherwise, why bother doing the training? In which case, it can't be too difficult to arrange for this properly equipped aircraft to be used for training, can it?
I am convinced that most of the people who do the IMCR have not realised that to make proper use of the Rating they will need a properly IFR-legal plane. Very very few students know the equipment regs, FM immunity, etc. It's only when you become an owner or a group member that you start to learn stuff like that.
I spent more time digging into this than most but still found myself nearly purchasing a share in a private COFA plane with a duff ADF - after explaining to a group member (who is a multi-engine IR instructor!) that I wanted to do my IMC Rating in it and fly it afterwards. As they say, go figure!
If training for the IMCR but in VMC (with foggles and a safety pilot) which is how it's normally done then the aircraft does not legally need to have anything in particular working (beyond the VFR equipment).
I suppose that someone might question charging a student £120/hr for NDB hold training if the ADF barely works, or is installed right over at the other end of the panel, etc, etc, but if you start doing that you will question an awful lot of things in this business.
It would be nice if there was at least 1 aircraft available for IMCR training in which everything worked 100% but I've never seen such a plane operated by any school. I am familiar with one setup where such a plane was available to a school for advanced training but not available for subsequent self fly hire (for obvious reasons!) and there were no takers.