I'm very surprised North would deliver a main without grommets in the foot for the reefing
lines to pass thru - what were they thinking? If that's correct, I'd take the sail back and ask them to finish the job, whoever cut the sail missed what should be a standard feature, for each reefing cringle you need a matching grommet in the foot, unless it is a loose foot main.
If your reefing
line turns at the back of the boom, your reef will not set properly if the reefing
line is not tied back onto itself, the cringle will be pulled down to one side of the boom, not to the center.
You do not want to install anything on the side of your boom, getting hit on the head by the boom is painful under any circumstances, being hit just by a block or a metal eye strap can change what otherwise might be a painful bruise into a fractured skull