That looks like it should work to me, I really don't know what those GC guys are talking about.
Like Matt said earlier, if you use some dental floss, strung up nice and taught with tape on just the outer strings,
you'll get a very accurate idea of where the strings will be on the fretboard, and where to set the pickup/route.
That also can be fine adjusted side to side, with very minor neck shifts, and/or grooving of the bridge saddles.
