Another option I'm testing --

-- drill a "properly sized hole" about 2.5" deep into a 2x (angle the
holes just a bit)
-- screw those to the wall studs (24" oc)
-- put 1/2" blackpipe (or 3/4" EMT) that fit snugly into those holes

Earlier someone had a photo of this idea. That was my original plan,
3/4" EMT that is 2.5" deep in the wood and extending 12" out of the
wood, seems to be able to support over 100#

The challenge is drilling the right size hole. Plan to get some
spade bits and grind them to the right size (OD of pipe/EMT)

The risk is the pipe pulls out of the hole when moving lumber
around.

I don't want the brackets themselves to take-up a lot of space. 1/2"
black pipe, or 3/4" EMT is ideal.

The idea is not to be able to store 100s of board feet of material,
but to get the bit I have off the floor and easily viewable and
sortable.