Keeping your animals at high temps is more likely to lead to slugs then not dropping temps for breeding.
91 for an adult female is over killed IMO, I don't mind keeping hatchlings at higher temps also I don't even do it anymore however adults only get a hot spot (when they have one) of 88 at the very most.
As for dropping or not dropping it's about what work for you and your animals, there are many different ways to do things whether it's simple husbandry or breeding, found what works for you and don't worry about what other do.