That is not a good plan.
You save much time, wrenching and frustration if you simply set shock length and preload before installing, while on table.
Belive me there is reason to doubt that numbers on this BSB shock may not be in ballpark for stock bike.
If shock length is way off then you crank some unreasonable preload numbers just to get the bike steering (rear heigth).
Simply set length to 314mm (adjuster near top joint) and check that preload is not far away from 14mm (less for 120 spring, more for 95 spring). To have preload number you find out what is "free length spec" for this spring type and substract spring length "as is" on unloaded shock. Race shocks have stronger topout springs affecting sag much. You get preload number right and then there is no need to measure sag.
Stock link may work ok unless spring (and high speed valving) are light or/and you weight is high, since shock may be at hard side.
Gen4 race: high spec.
Suzuki GSX1300R Hayabusa 2013: stock.
Kawasaki KX450F 2016: love it.