Please can I help a little?
The Crown Estates granted a lease of the property some years ago to Galen Weston. Although Galen Weston is very well known as the multibillionaire owner of Associated British Foods and a number of very well known shops round the world [Holt Renfrew in Canada, Fortnum and Mason in London, Brown Thomas in Dublin etc] he is very well known in royal circles because he was the patron [owner] of the Maple Leafs (sic) Polo team for which Prince Charles played many times.
I am sure that Galen Weston would like to 'stay put'. He has family including a son, Galen Weston junior, who I am sure likes Fort Belvedere.
Would think that William and Catherine might prefer Gloucestershire: Prince William plays polo at the Beaufort Polo Club.
Hope this is of interest,
Alex