If you're choosing between a LOR from a HS instructor and one from an employer, go with the latter. Ideally, you would want to get another from a college professor. If that isn't an option, a LOR from an employer should be fine.
do american students apply via lsac? i am so confused because as a canadian who wants to get into a school in ontario we use OLSAS. I am wondering if OLSAS keeps LoR on file for an extended period of time
@lmekahel Sounds like a plan. Still, I'd recommend that you also get an LOR from a professor whose class you took (not the dean) at your primary college.