The idea sounds nice in theory, but after years of trying out “ultralight” chairs and benches, most end up too heavy or bulky for longer backcountry trips. They usually start to creak or sink into soft ground, too. If weight’s a top concern, you might get just as much value from a closed-cell foam pad. You can fold it for sitting, use it for your feet outside the tent, and it’s multi-purpose (plus, no worries about breakage).
If you love the bench concept, maybe look into modular designs with removable legs, or even DIY setups using trekking poles for structure-it’s a trick some thru-hikers try. I’d only carry a bench if I was basecamping near the car, honestly. But curious to see if anyone’s found a truly durable, light model worth its ounces!