Ok, so I couldn't find the explainer and it took me a minute to figure out the math. LOL
So, most cats increase at .25u. For a cat that is on 1 unit, that .25u increase is really a 25% increase in insulin. At 14 units, by increasing only a half, you'd only be giving Crystal 3.6% more insulin. Comparably -- not really that much of an increase. If you increase by 1 unit, it'll be more like a 7% increase. To hit that 25% increase, you'd be talking about increasing by 2.5 units, which I would NOT recommend. Some people, if they reach 20 units, they increase by 2 units at a time -- again, a 10% increase.
FWIW, we started using the R insulin when Cobb hit 14 units. The day I increased him to 14 was the first day I gave R. That's on the second tab of his spreadsheets.
Here's the thing about high dose cats that all of us who have them have learned. The protocol doesn't necessarily work for them. It gives us a good road map, but they will deviate off the path. High dose cats write their own rules. Boy do they write their own rules! You may not see any change at 15 units, but if you hit 16 units, it could be like a light turns on and they drop. ECID, I suppose. (Such a frustrating expression, isn't it?)
If Crystal were my cat, with her numbers, I would start increasing every 4 cycles by 1 unit until I see numbers under 200 and then reevaluate.
IF Crystal has IAA, you have to be aggressive in the dosing to get ahead of the antibodies. It is a PITA. Those little boogers are fierce. If you are aggressive, see progress, and then see a dose "go bad," without the IAA test, I think it would be safe to assume she has. Testing results are always nice because they back up a theory and can support your treatment plan, but they aren't the end all be all, IMHO.