I would be interested to know who they are planning to talk to during the drop. At w/e Boscombe is likely to be closed and GA traffic could be using either of the narrow routes from the SW, either above Boscombe's ATZ and Thruxton or via Chilbolton.
At least Old Sarum's skydivers can be listened to on Old Sarum Radio when Boscombe is closed and, even there, I have had one close encounter with their aircraft as it made a rapid descent after the drop. A rapid descent from the proposed drop zone back to Popham is likely to be quite dangerous.