This particular question has 2 sides of the table.
IMO, and based on what I have read and use personally.
It boils down to a ball pythons traditional enviroment. We all know that ball pythons are nocturnal. During the day in lets say Ghana, typical temps are near the 90 degree mark plus or minus. This lasts for many months of the year. During which time, a ball python doesn't seek out the sun, but hides in a safe and darker area while it sleeps during the day. Supposing those are its primary habbits, it is almost impossible to assume that its the same temperature in its hide spot, as clearly it would be cooler. Given that, as it transitions itself from dark and cooler temperatures in the day and then outside at night where it has then cooled off some. Technically speaking the temperature offsets itself enough through this process to only fluctuate a few degrees plus or minus. Giving the ball on average of a constant 83 to 85 degrees temperature daily. Only then for those few months that it does get cooler do they cool and go into breeding mode.
So to answer the first post, yes its possible, very possible. Thats exactly what I do. I have a complete climate controlled room for heat and light with about 76% humidity at all times. The room is super insulated and at 84 degrees from 7am to 5pm with light during those hours and 14 off dropping the heat to near 72 degrees. Prior to the breeding schedule it was 84 degrees 24/7. I have started cooling for the past week and it works wonderful. With a few balls already reacting to the temperature change.
So to respond to the first reply on your post, IMO it doesnt matter gradient or not, and both metthods achieve the same results. I've never had one sick ball as a result of my methods, get perfect sheds, and hatched out healthy babies.
Lastly one important thing to remember is that heat rises. Witout a fan to circulate the heat, or without a well insulated room, then the heat will be different from the top of the room to the bottom.
This is just my opinion and hope this info has helped.
Jeff & Starr Morrison
5StarrMorphs