Unless you always have a nice flat and level surface upon which to set up, you would most likely be better off with a tripod arrangement.
The 4-legged benches and seats have a tendency to rock unless perfectly set up.
Seperate seat from bench, another source of vibration.
Suggest you comtemplate the use of heavy-schedual PVC tubing for portions of the bench.
With removeable caps on the ends of tripod legs, fill with sand/gravel/dirt/rocks/water for weight, and drain when ready to go home. For sand and gravel. a funnel is handy. Done right, it folds flat.
Benches have their uses, but they are limited. Unless you are practicing bench-rest shooting, they will teach you nothing and may interfere with learning to shoot well from field positions.
Unless you are already an accomplished shot from all field positions, consider getting a good shooting mat instead. FWIW, and YMMV.