I'm going to start this off by saying my liability spiel. I'm not suggesting anyone do this. At your own risk, all trees are different and rot might present, etc.
I thought I would share something that worked for me on a really difficult tree.
Big cottonwood well over 3 ft in diameter went up about 20 ft. Then it split a bunch at 45° angles. Still about 2ft diameter. Angle was way too much to work with any of my hang on stands. I've been staring at this tree to figure out how to put a stand in it for a week.
I brought in my 28 ft extension ladder. It's my hunting ladder and it's painted camo in each room is completely padded. It is whisper quiet to use and it really doesn't stand out very much.
Basically I took a bunch of 3/8 in eye bolts/hooks 10 in Long. Worked like a charm. I pre-drilled them out with a smaller diameter bit. I would only use eye bolts going forward. I set two stands this way one using hooks. The hooks are pretty secure but it is possible for the cable to pop out and I didn't prefer that. In that case I used three hooks. Two is adequate but I like the comfort of three.
I made sure everything was sunk at least 5-6 in. Also so the hooks were not directly in line and at a slight angle to the direction that the cable was going to pull on them. This uses the side friction rather than just relying on only threads.
Things to keep in mind. While a 3/8" bolt is very strong, if it's got 4 inches hanging out of tree facing away from the stand, your weight will want to bend it to the middle. I had to put a rachet strap on one to stop it from bending. Ideal angle in towards the stand is better if the tree is wide enough.
I will say it was very solid.
Negatives:
Took a while to do probably 30 mins just for the bolts. Putting stand on was fairly quick.
Also some guess work (guessed correctly) to determine where to drill them for eyelet to be right when screwed in.
Worth negative but was manageable was that due to the angle the area in the front of the seat you stand on was 1/2 platform and 1/2 the teeth that hit the tree.
Oh it was a little sideways so I lag bolted a 2x4 on the tree to even the stand the direction I wanted.
Lastly, the ones where the bolts were angled out I ended up taking a 2x4 and cutting notches in it with the sawzall and making a spreader bar.