Exploration of TFD and the moral "ownership of digging rights" really rested with the discoverers - it was (still is?) very much "their baby" as they'd found it after a huge amount of graft and very well done to them and what a massive moment in the history of Mendip Caving and Digging/Exploration. To a large extent I would imagine future digging say-so should include their assent but legally that probably rests with the landowner(s) - someone more knowledgeable than I can answer that.
Back to now. When/if access to RH and TFD resumes does this mean that the landowner will call the shots regarding continued exploration works, unilaterally, or is there a moral case to be made for future digging to be given secondary assent from the original discoverers? I'd say the latter/former combined. Furthermore who would be "in on the digging" there and how would that be selected? There is almost certainly a massive amount more cave to be found, and probably without too much difficulty.