Hot side temp with vs without hide. Am I being too picky?

So have a small 2 level rack with a thermostat setup for a target temp of 90 degrees. Without the hot hide in place, the surface temp in my tub is coming in at 90.3 at the warmest point. When I add the hide itself over the hot side there is a thermal gain of 4-6 degrees bringing it up to about 95 degrees. Obviously the hide is helping to insulate the area and raising the temp. I've checked this both with a metal thermometer probed left in the hide/on the surface and with an instant read thermometer gun. (This is without the snake in there.) Is this the expected impact of the hide and within standards or should I be dialing the thermostat back to hit 90 with the hide in place? Current thermostat is on/off style and is allowed to osscilate between 87.5 to 89.5 and will just cross 90 degrees due to lag on the high side.

I'd be dialing back the heat to keep even the hide temperature within a safe range (ie. under 90* max). Not the optimum t-stat for this set-up, obviously. Yes, heat can build up in a hide- you might also try moving the hide so it's only half-heated. But keep in mind that snakes often slide them around also- you still don't want to risk it being too hot, as damage or death can result.