Glen Lyon has been a notoriously bad estate regarding access for walkers for a long time.
Glen Lyon Estate is at the Fortingall end of Glen Lyon. I’ve not heard of any access issues there.
Presumably you mean North Chesthill Estate Alex – who basically don’t want the general public on ‘their’ land.
Also the other year I popped up Cam Chreag, I parked in the excellent car park, near Innerwick in Glen Lyon, complete with spotless toilet facilities provided for, without charge, by the Meggernie Estate.