I'll give some of the lightweight 'real' packs a look, z-pack is a bit too much 'save world/green new deal' it appears.
I had an Equinox small frameless pack years ago and remember not liking it. Bought it for predator hunting, foxpro/decoy/water/snack etc. , I'd as soon carried a nylon handbag.
60 ltr @ 2 lbs. is plenty light.