I'll pass on cannabis infused lard.
I do have a quart jar of home made infused coconut oil and it works very well in a number of recipes. Ever try cannabis infused honey? It's wonderful stuff ....
Anyway, back on topic ... there's a lot of people who will keep the larf and use it to make their infused oil/butter or whatever. However, I prefer to trim it off for the very same reason that @RootsRuler mentioned ... We'd rather the plant utilize its energy on developing the tops that are growing in the canopy.