I thought about raising the floor but it’s hard work to load the boards in on your own that way . I was considering putting a sheet of ply down one side and standing boards up against it with a board prop
Rack down one side floor to ceiling for all your tools then buy 2 x buckle straps from wickes, screw one at one end and the other at the other, cutting the buckle off 1 side. Stack boards against rack and do the strap up to stop them toppling. Just not too many boards and sharp right hand turns!