I run ambient only in my snake room and it runs between 84-88. I have a separate rack in another room that I use for quarantine that has a normal heat tape setup. The only thing that has heat tape in it in my snake room is my incubator. I have experienced zero difference as it pertains to the animals doing it one way or the other. It is just easier for me to run ambient only for the majority of my collection. A lot less failure points to check.
When you say 84-88 does that mean you adjust based on time of year or you just have that much fluctuation in the temp?