It's clear from this thread that "ultralight" means different things to different people. Maybe two threads are needed.
My suggestion would be a discussion of why you would want to carry the additional weight of FF (+lenses) on a hike, (unless Nat Geo IQ is the priority) ???
Ansel used hiked/climbed with 4"x5" -- and I climbed 2000' to the top of Nevada Falls (Yosemite) with a full-backpack of 6x9cm -- back when that was needed for "good" IQ.
But NOW I would only do it with either a RX100xx -or- FZ300 -or- FZ1000 -or- RX10-III or IV, (depending on priorities and if I the "time" often required for best "lighting" etc. to make it worthwhile).