Good morning - I don't see a condo for you guys yet today so I'm replying here.
Unfortunately, I don't have any suggestions since we are struggling with a similar cycle. Callie also has fast steep drops early (mostly in the day cycle) and then mini bounces or loss of duration resulting in higher numbers. As Bhooma said, we are also feeding raw and I actually stopped trying to slow Callie's drop with higher carbs at +1 because that seemed to negatively affect duration even more

Why don't these cats FOLLOW THE MANUAL??!!
Since Callie nadirs so early, there is also no way to stop feeding her at nadir. She would for sure start eating me alive
Good luck with your feeding experiments! I'll definitely be following 'cause I am probably going to have to try some experimenting myself again soon if we can't get rid of these blues...