I remember seeing what looked like a clear cuttings pile of
wood with a tree in the middle of it posted some where on this site but I'm not finding it with the search terms I used (deer, deer trap, deer hazard etc)
The posting person took scrap cuttings of wood/saplings and arranged them such that the deer could not walk thru them with out risking a sharp jab or stepping on a rolling/rocking limb (the roller was constrained from falling off in either direction. The pics showed arrangements about 2.5 to three feet at most in height and were about 4 to 5 feet in breadth all around the tree.
It was clear from the pics, it was a dangerous to walk and even more dangerous to try to jump (no where to
land except on the tree), for the deer. Deer will go under and over but don't like unstable semi moving objects they would be required to stand on (especially when there's a chance they'll get stuck or stabbed in the attempt). I've never seen a deer in the middle of a clear cut pile.
...I wonder if a person could create round 12" hazard balls to create a 4' boundary around the tree (something to keep the tree from being crushed in the middle), with something beneath the balls physically dangerous to the deer......if you had jagged sharp scorria in 10" size, that would work too
what ever you do is going to be
alot of work ..... I think a real risk or perceived risk of motion to the deer's feet would work like you've sort of done.....please let us know how well it works