So uh, I've used a dog bed called a "coolaroo"

I guess its kinda like a cot, it has a tube framing where you
can get good purchase with your feet. The material is a bit scratchy (probably why the dogs don't like it lol) so I'll put a blanket on it. Good for plow with legs spread apart.
I'm a little sketched out about how sturdy it is or isn't, so don't take this as an endorsement necessarily.
I've also done X in my hammock, but I do get paranoid about falling out of it.
I almost fell off a weight bench once, right after orgasm in plow, so, I've definitely been more careful since then.
The bed is definitely my preference. Comfy
Polevaulter:
I've seen bean bag chairs recommended a couple times now, so I will get one and try it out
Also maybe relevant, I've had the idea for a long while, of building a "nest", just a nice, private, comfortable spot outside, to hide out and have sessions. Not sure exactly what that looks like yet, but maybe I'll share that if I do eventually put it together.