I'm afraid that the CAA may chose to ignore these issues. If gliders (the real problem sector in this) can be fitted with a current Mode S, even if they need an extra battery, then all other users (except, perhaps the microlighters)will lose the reason to object.
German and Dutch glider pilots are already fitting out, and, as I understand it, will switch on the tx for the duration of their flight within the designated airspace.
We do have a long-ish transition period, though