There is no consensus that CRoW will override the mine and quarries act.
I am aware that a member of the BCA executive (who is doing a shed load of work on CRoW) believes that non-working mines will be covered but it isn't shared by many.
Further, the Cambrian Caving Council (Welsh arm of the BCA) are making no proposals in that direction.
Ian
A door, once opened, may be stepped through in either direction.