That all makes good sense. You're right. Good way to save a pound. You seem to be at a weight level where you could probably go frameless, or at least try it. I have a GG mariposa, it's 27 oz., 2 ounces more than the gorilla that was probably more than I needed, but it carries like a dream. I also have a 7.5 ounce Zpacks zero. It's my only frameless pack, but it carries a lot and is extremely comfortable. Short of winter, its getting lots of use.
I mention this because the Zero starts at $75 and includes a frame option – which I think is $30. I got one with mesh back pocket, water bottle pockets, removable webbing waist belt, and a few other options, came in around $130 and is really quite comfortable. Knowing what I know, and that they take less than a week to build and ship a custom pack, if I were you, I'd get the Arc Blast. I know I would be very into the venting ability of the arc shaped frame, and Joe is great to work with if you want something different or special. I'm sure the MLD is great, and maybe better for off-trail, though Zpacks hybrid material is likely as durable. Lots of Arc and Exodus threads on here.