I dont hunt blinds much but I will distill my limited learning. My hunting has been close enough to a vehicle that weight was less of an issue so some of this may not apply.
- For long sits, get a chair with a back rest.
- have a pee bottle or two
- I tried a few light chair and never found something I was crazy about
- I have a millennium swivel chair but it is a heavy bitch.
- I have had better success just using folding tailgating chairs but also not light. Look at the gci director chair if you go this route.
- last point is practice your shooting position and shot if you can. I muffed an easy bow shot because my bow was hitting the top of the blind. My limited experience suggests you May have to take a shot from an awkward stance or position with your rifle or bow.