Nonsense.
Not talking of a bare frame, no need to build a 1bike to fit a harness
how long does it take to disconnect a battery,remove tank, [one bolt, two nuts], disconnect old wires, tape and so on, remove old harness replace new clean harness, connect to all existing terminals and earths, tidy up with nylon ties, and reconnect battery?
Two hours, inc tea and cake, admittedly missus brought that to the shed.
Two spanners and a screwdriver needed, one 7/16 af for the earth terminals, a 1/2 for the tank and headlamp bolts just to loosen them, [oops forgot one for fuel pipes].
I have done it many times admittedly, but even a novice should be able to do it in an afternoon.
FFS, a new harness comes in a lump, just join the ends up to where the old ones used to be.
With everything to hand, correct wire colours, clean bike, I can make up a new harness from scratch in a day easy, soldered joints and all.
Too much nervousness and BS talked about electrics.
rule one, earth everything to the frame pref one point.
rule two think of it as a water pipe insted of a wire, what goes in one end has to come out the other; if it doesn't its either blocked [no connection] or diverted and coming out of a leak [short circuit].
simples
sorted
bedtime
I wish I could get hold of the mugs paying for these sort of hours.