If it were me I'd find out what he was shooting before and what type of rest he has.
If he is using a bisket it doesn't mater if the are helical but you need to put the cock on top. If he is shooting a prong it depends on his setup. The veins may need to be dead on lined up with the center of the shaft to prevent contact and cock down.
if he is shooting a drop zone, rip cord, or hog a slight offset will be desired.
If you install the knocks, assuming they are standard don't glue them in. He can make the adjustments as necessary for clearance.