It's curious how you use such a big temperature range. I've never used a pinecil despite having friends telling me very good things about it, which picked my interest a bit.

Can you tell us what exactly do you solder at 320ºC and what is the exact type of solder you use and/or Pb and Sn percentages?

Also, is your pinecil calibrated? And which tips do you use at that temperature?

Anecdotally, what usually happens to me at lower temps is the tip and/or the solder wire sticking a bit while I'm soldering which I take as a sign that the liquid solder won't flow correctly and that I have to spend more time giving it heat from tip, than I should.