Hi Alex. I'd make the vermiculite in the laying box damper - same as you propose for the incubating medium. You need to keep the dust down (which can be dangerous to them & us if inhaled) and they seem to appreciate higher humidity when laying. It'll also help keep the eggs "fresh" if they lay while you're out and you don't find them for a few hours.
I use plastic tubs like that for incubation and I keep them off the heat mat with an inch thick layer of larger grade vermiculite (allows air circulation).
I use plastic tubs like that for incubation and I keep them off the heat mat with an inch thick layer of larger grade vermiculite (allows air circulation).