I don't see that this item is for ambidextrous use.
This "EXPERT " said this isn't an ambi kit?! THIS IS AN AMBI SAFETY SELECTOR KIT. The answer to this question is: No, you can have a single safety only, you'd just put the bolt catch side in, which is held by the grip spring and detent, then put the other sides screw in its hole. That should work if you don't want an ambi selector. It may not be something that's made for that though, so it may be a little odd on the opposite side as far as grooves for the unused selector. I would look up f1 safeties to see what they say specifically. But it will definitely work to run a single
This "Expert " said this isn't an ambi kit?! It has an ambi safety selector. I would look up similar f1 ambi safety kits to see if they're similar to this included one, and if you can run a single safety selector