You know how you can build a bridge to rather impressive dimensions with just one dwarf? What if scaffolding was three-dimensional multi-tile construction of basically up-down staircases that I could lay out in a large volume, constructing and deconstructing from a single tile.
I like this idea sort of, i guess im not entirely sure what to make of it, but in the same, how about segmental 3 long with a down and a upramp on either side prebuilt. Positioned in the cardinal directions and also adjustable in which direction the ramps face requiring supports with a adjacent wall or underneath itself, you could build a ladder quite easily with it and build it out of 3 logs or blocks per piece.
(+) = is the wall, ▒ is just the floortile i've chosen to demonstrate the scaffolding.
▼ +
▒ +
▲ +
From that you could build either a chain of supports (connected by the upramp) , ignore the ramp and continue to the ramp next to it supported by the wall
▼ + 1.
▒ +
▲ +
▼ + 2.
▒ +
▲ +
Scaffolding upramps elevates to the next level or to higher scaffolds, while the downward ramp on example 1 would bring at floor level people onto the same connected z level of scaffold 2 connected to 1 supported by the wall and so on and on at cost of wood logs/blocks
edit - i think i got the ramp ordering correct this time, crisis averted, play with swapping the ramp directions in order to span more distance across a wall.