mostly vertical pressure not at an angle.............and if all your 90k was on the saddle the front wheel would be uncontrollableEqually, physics tells me that if the dropper post can take my 90kg sitting on it, whilst going over rocks, roots and compressions, it can also take the weight of the bike it’s attached to.
As it happens, I don’t hang my bikes by the dropper, but that’s because I lightly clamp the top tubes, which in my bikes are all alloy. I’d have no qualms hanging from the fatter section of a dropper post though if my frames were carbon.
Seriously what we are looking at in terms of forces with a clamp on the seat post is a best a 200mm section being clamped and the forces acting on it are both vertical and horizontal resulting in a vector of probably 60 degrees and that bears no relation to the forces applied when riding.
If you were trying to bend the dropper post that is the vector of force you would apply with a long lever.........ie in this case more than the front centre of the entire bike. you would get nowhere trying to bend it by sitting on it!!