I agree with this as it lets the snakes with strong feeding response know it's not food time. I do this with my aggressive feeders who tend to be in food mode.
I've had my snakes for almost ten years and there are times where I don't handle them often and haven't had an instance where they "forgot" me.
With that being said, the hissing sounds very defensive and that can be for a variety of reasons. I'd start with double checking your husbandry and then also give your BP a break. Is your terrarium located in a quiet place?
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