Net setup - all good but high humidity

[Homebody]

I will raise the temp of the heat mat a bit and see what that changes the surface temps to and see if that helps.

If not -

Would next the best way to do this simply cut out a 6' or so diameter hole in top - cover with some mesh and fashion a heat lamp directly over the top and monitor closely?

No. You can't raise the temp on the heat mat. That would raise his basking temp too high. It wouldn't wouldn't lower humidity anyway. In your previous thread, you proposed using a small space heater to raise the ambient. Did that not work?