If the pre-punching in the -9 has progressed to the level found in the -10, you won't need the procedure (or I should say that the Z-brackets in the -10 are pre-drilled so the procedure is moot). I'd be interested to know; Van's keeps improving the kits in small ways.
Doing it Van's way (even as described in the manual 5 years ago) works just fine.but almost think they would come out pretty good even if you did the way Van's suggests?