I don't have any advice, it sounds like you're doing everything I would try.
If you wanted another disaster story to make you feel better, I had opted for my first ball python to be an adult (i.e. established eater) in my attempt to avoid dealing with the fasting straight away or difficulties getting a baby adapted and eating. So, I went to an expo, got an adult male, brought him home in October. I had seen the winter fasting, but thought I would have at least 3 or 4 feedings before then, not realizing how randomly they decide it is winter. (I'm in Texas, so winter isn't too evident until November-December most years as far as temps go.)
So he fasted on me for the first 5 months I had him. Since he had supposedly been fed live and frozen, when I offered live, he would take a mouse or small rat (what the local place I could get live feeders from happened to have) every 3 or 4 weeks. So maybe half as much food as he should have had weekly he ate every month.
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