No, its all amazingly well thought out (by Securacat). The three big trees, including the plum you can see in the picture, have 'collars' that stop the cats climbing above 6 feet (you can just see it in the photo). All other trees and bushes have been cut back so that there is no possibility of lauching a bid for freedom. Flynn is an Egyptian Mau (at least as athletic as a burmese) and it has kept him in for seven months now. The whole system is brilliant. When Secruacat discovered I had a Egyptian Mau they suggested that we took no risks and we did everything they suggested (including cutting down two trees and pollarding two others).
Putting the pergola in the middle of the garden was my idea (before the catproofing it was at the edge). Flynn loves climbing all over it, sitting on it and surveying his domain.
OH called the project Stalag Luft Kitty when we first started out but he's got used to it now. Actually, it is amazingly unobtrusive.