Nice to see everything working out for you.
I have a question though, why is your bottom vent closed during the cook?
When I use lump in the KP, I rarely need to open the intakes. Maybe just a hair sometimes.
Once I start to see the temperature drop below my comfort level, i.e. about 550° or so, then I open them up.
Plenty of air feeds the fire from around the edge where the KP rests on the bowl, as well as the opening.