I don't see a more recent thread for you so will go ahead and reply on this one. I'm glad you've decided to increase by 0.5u every 4 cycles. In my opinion that's the way to go at this phase. We've fast-tracked other kitties before and as long as you continue testing at the rate you are doing, it's safe. You'll be able to get him into better numbers as quickly as is safe to do so. When you start seeing blues, then you slow down the dose increases.
As far as maximum dose size, in my experience it really helps to keep the dose down by being somewhat aggressive with keeping your kitty in normal numbers. When I started there was one person who was afraid to have her cat get into green, even at the lowest doses, and she basically spread the word to let acro cats stay above 100. It just seems that when people do that (which I did) the dose continues to climb. Higher numbers cause
Glucose Toxicity, which requires increasing the dose even more to get the cat's body back into normal numbers.
On the flip side, those who keep their cat in normal numbers seem to be able to keep the dose down. The risk of doing that is that if the tumor suddenly stops putting out growth hormones, you could end up with the kitty being overdosed and have a long time dealing with it. You should always have 8-10 cans of high carb gravy food on hand, just in case you need it. Choose higher high carb foods, like over 25% if possible, and know that you can increase the carbs in gravy by adding a sugar syrup like corn, maple or honey to it. I have HEARD people say that acro cats could need more carbs to be brought up, but I didn't personally EXPERIENCE that with punkin, nor have I seen it happen with the high dose cats here. This is a case where "know thy cat" is essential.
When we started there was another cat,
Tommy, who was diagnosed with acro at the same time as Punkin. Tommy's IGF was 313, Punkin's was 281. After diagnosis, I let Punkin's nadirs drift up over 100. I didn't increase his dose by large enough increments, staying with 0.25u increments even when we were close to 10u. Lauren kept Tommy tightly regulated even after his diagnosis. I had Punkin treated with SRT (which I think was a good move), but I also did dose reductions in advance, anticipating he might go into low numbers and fearing (from people's stories) that I might not be able to bring his blood sugar back up. In my experience, I could bring up his blood sugar just like everyone else did, with a teaspoon or so of gravy. But there was all this drama on the high dose group around the time we were diagnosed and I was a bit adrift in what strategy to follow and was getting competing advice.
Lauren continued to follow the Tight Reg Protocol and she didn't do any other acro treatment - Tommy lived 4 years after his diabetes diagnosis, to the ripe old age of 20. Punkin died 2.5 years after his diagnosis, about 18 months after the SRT. He had a lot of things wrong with him, so I don't think what I did harmed him. His thyroid was killed by the SRT, and while I knew that was a possibility, I was getting it checked regularly. What I didn't know was while the general tests for thyroid (T-4) were showing his thyroid was fine, he wasn't. When we did more extensive tests (free T-4 and cTSH) we discovered his thyroid was extremely low. Thyroid is critical for controlling pretty much all body systems. He also became anemic.
Anyway, that's all to say that if you can't afford extensive treatments, don't despair. Carry on and treat with insulin.
The most important thing you can do is to learn how Bronx works and responds to high carbs when you do get to the point of dealing with low numbers. At some point you will.
Ask as many questions as you have. Feel free to tag people with high dose kitties if you need their help.