I vape until it's dark brown even though I suppose it's likely that there are no more compounds to volatize by then.

On my Da Buddha unit, I keep the knob at about 1:30-2:00 o'clock.

I don't usually use the long poker (which is way sharper than it needs to be, by the way), but I do tap the wand to stir the stuff up, pretty much every vape.

Personally, I wouldn't leave herb in the vaporizer while I did something else. I think it would heat up enough that the compounds would boil off, leaving you with straw, basically.

If you fill the wand with barely enough herb to cover the screen, you will have enough to vape but not enough that you would want to leave it there. I find that the smallest amount at once is preferrable.