Wow! Some good ideas thereThere were a few nuggets of wisdom decades ago when I started lightening my load. One was to get the lighter pack last, after you'd pared everything else down. I've seen a few people cramming too much stuff into a light pack and be unhappy about it.
Another was to reduce clothing to the point where you can wear everything at the same time, as part of a coordinated layering system.
Another was managing consumables, and that was perhaps the hardest lesson for me. Don't bring extra food or fuel. You won't get in serious trouble if you skip a meal. Don't carry extra water if there's plenty on the ground, which is often the case on the AT.
Another was to spend a lot of money on the sleeping bag, and get the best down you can afford.
I had to look up the volume of my pack--it's a 42L Gossamer Gear G4. I've hiked 200+ miles/eight days between resupplies with it. The final gear change that allowed me to do that was going stoveless. That and many of my techniques aren't for everyone, but they work for me. You'll need to develop your own system and it will take time and a few gear changes.