In the wild any reptile will not maintain 30 no matter where it lives
Mine have the option of 26/30 if they want it
Then they have the option of 20/26 in the fanned area
Unless just before shedding or after a feed they prefer the cooler areas most of the time
They go outside virtually every day so get plenty of direct sunlight when they want it
But even outside they may lie in the sun for a hour or so but then back under cover
They are very responsive and love being handled etc
But if they were kept at one temperature I think they would feel uncomfortable when removed from that "Security Blanket"
Imitating their preferred natural habitat/temperature works well for me
Remember that even Darwin can drop 15 degrees at night