How to keep heat away from an electronics enclosure?
An enclosure under the hotplate will work perfectly fine, provided there is an air gap, the existing rubber feet would be sufficient, The hot plate creates convection currents of air that pull cold air in from the sides. If you wanted to run the hotplate continually at very hot settings (&gt; 200C) then a thin metal plate spaced 5mm above your enclosure would add additional &quot;insulation&quot;.
I've got almost exactly the same hotplate, and I just used a piece of 10mm plywood, screwed that to the base of the hotplate (after attaching a thermocouple to the central screw under the hotplate), and then attached a plastic framed 1/4DIN temperature controller next to the hotplate, this worked well, I only used it to about 210C to reflow solder.
(a) Normal mounting under hotplate unit:

(b) Add a metal spacer plate if using at high temperature for extended period, or heavy items on hotplate and a plastic enclosure, a piece of thick aluminium foil (from disposable baking tray would suffice) air gap &gt;= 5mm.

(c) A sheet of plywood works fine under the hotplate, it is what I did, it gets a bit warm on top (but not as warm as if left in the sun!), the wood didn't warp, so can't be &quot;too hot&quot;