@TrickyDick I can tell you what I do, if it helps at all. I'm using a Bullet with the IBITs module, not sure if you have IBITs but if you do not then just ignore the following. Also I use Celsius.
I do a 240C preheat for 30+ mins. I'll charge it with 1lb of beans, P6, F2, D9. At the 1:30...