Spot vs. Ambient temperatures

[snakeophile]

Coastal carpet, 6 months old, 3 feet, 140 grams, feeds on 3 hopper mice every 7-8 days.
Viv is glass with screen top that measures 4 feet wide x 3 feet high x 2 feet deep.
Heated with Pro Heat RHP model PH-125, 425 BTU/h, 125 watt, 15" x 24" x 1"
Temperature controller : Herpstat 2
As my coastal carpet python has grown, I replaced the grape vine with manzanita to give her better support. High up, on the hot side, I've noticed that this wood retains heat to the point that it frequently reaches a surface temperature of 97 degrees even though the ambient measures 90 . Consequently, the snake stopped perching and frequently retreats to a hide on the floor. I don't know why she didn't go to a lower (cooler) perch. To get the surface temperature of the manzanita down to low 90s I had to lower the ambient to low 80's. Is this a healthy situation for a carpet python? What changes would you suggest?