This is a common thought. Unfortunately, getting him used to yellows isn't a way to help bouncing. You need to get them used to normal cat blood sugar values. With SLGS, this means getting them to a dose where they see numbers between 90 and 149 as quickly and safely as possible. There may be some short term bouncing, but bouncing is a perfectly normal mechanism. Pretty much all recently diagnosed cats bounce. Be glad your cat is bouncing. It means the part of the system that keeps him safe from lower numbers than he is used to is working fine. I tried to think of bouncing as the inevatable result of the insulin finally starting to get my girl into better numbers.
There is a down side to holding numbers too long. It's called
glucose toxicity. Sounds worse than it really is, but it means that a cat gets used to higher number. Once a cat develops glucose toxicity, it takes an even higher dose to break through to get good numbers.
What food are you switching from and too? The Natures Variety rabbit listed in your signature is still low carb. Rather than just saying "old food" and "new food" on the spreadsheet, it would help to say which ones.