As you already know, the terrain and cover influence the height.
In my 51 years of bowhunting I've been at 10 feet (cedar trees or multi-stemmed hardwoods (cover) and nearly 30. The 30' was a fluke, the tree I wanted to be in, near a button-bush swamp had a perfect limbs and cover at that spot.
I prefer, about 15' because the higher I go the steeper the shot angle and tighter elliptical kill zone.
I spent my early years in interior forest with straight, limbless boles like you describe. My haul line was 21' long. I climbed (Baker climber) until the line became taunt. I'm happy to report that I was very rarely spotted in those trees. Of course movement had to be limited, and the time to draw had to be picked perfectly when the deer was less likely to catch my movement.
Sometimes, I have to remind myself, when the perfect set-up isn't available, that these deer won't just drop in that spot, they will have to come and go. I then look for a better ambush point, lower to the ground with better cover.
I am almost entirely an "edge" hunter these days.