“Subsection (1)(aa) above authorises the discharge or modification of a restriction by reference to its impeding some reasonable user of land in any case in which the Upper Tribunal is satisfied that the restriction, in impeding that user, either — (a) does not secure to persons entitled to the benefit of it any practical benefits of substantial value or advantage to them; or (b) is contrary to the public interest, and that money will be an adequate compensation for the loss or disadvantage (if any) which any such person will suffer from the discharge or modification.”