Buy a higher low carb food such as Wellness chicken/herring (6%) or turkey/salmon (6%) or Merrick cowboy Cookout (5%). If his weight is good based on what you have been feeding him, divide the daily food he gets into two portions. One portion for the a.m. Cycle and one for the p.m. Cycle. Then try to "front load" the cycle. In other words, from the cycle portion, feed him at preshot, +1, +2, +3. I think it works best to feed him a bit more at PS and +1 and the remainder at +2 and +3. Your goal is to slow the drops. It might not happen overnight. You will have to test a little more early on. I would always get a +2 test if I were you to see how fast he's coming down but I'd also get a +3 test. See if the food slows him some.
If you can slow him down a bit, he might not get so low. He might even require a little higher LOW carb food than I have suggested. Every cat is different in how carb sensitive they are.