Meant to reply ALOT sooner, but got side tracked. So many different options to look at.
As a number of you mentioned, the fact there isn't a popular system shows how difficult it is. What I would call a "daypack" might not be what others do, and that makes sense.
I'm going to check out all I can up there, might reply with some questions, but I'll give more thought on the packing everything in smaller compression sacks, bags and baggies.
My biggest issue was those parts of the backpacks that are "sectioned" for things like pens, hooking keys, etc. Everything fits great, but a PIA to move between packs!
For the record, my two packs are:
Osprey Atmos 50
North Face Neutron 32