There is no set rule for cooling James. If anybody tells you that then they are full of it. Every Reptile keeper keeps their animals in their own unique way. Every state has it's own set of weather patterns as well as photoperiod. It's a matter of trial and error, some get it right the first time and others could take years to figure it out. I commend you for taking the time and effort to log your observations and to share them on a publi forum.
I have found that pythons actually look for the cool end at this time of year. They know they have to cool down to be able to breed succesfully. We usually drop our temperatures over night to around 15 degrees. We supply males with even lower temperatures by placing them in the cages that are directly in contact with the floor. In a bank of four cages they would be in the lowest cages. We supply them with a daytime hotspot of 28-30 degrees. This hotspot is very localized as we use ceramic heat emitters. There is still a big part of the cage that stays cold. This gives them the ability to choose where they want to be. There is no choice involved with the night time drop, they have to be in the cold. We start to cool them beginning of June and keep them cool for exactly 6 weeks. We raise night time temps over 2 weeks and then introduce the males to each other. We observe them while they combat for about an hour. We seperate the boys for a couple of hours and then introduce them to the girls. This routine is followed every year and we have consistent results every year.
Don't mind the people that don't have anything positive to add, there are many of them on this forum.