Do you know anything about my other two inquires as to home test accuracy and microwaving the QF a few hours before my test (start work at 8am, test is at 10.30 am).
The home THC kits and the assays used for the initial screen function on the same principle. Neither are more reliable than the other.
The QF can be microwaved many times over, which is great for practice drills. To answer your own question, youd have to make a practice run or two to see if your body heat alone, is able keep the QF bottle at proper temp between 8 - 10:30 (after the bottle was initially mic'd). If not, then consider using the heatpad after mic'ing the bottle.