I think the switch to Lev is a good idea. Hopefully your vet is on board for writing a script for that. There aren't really any different written protocols for high dosers. We do larger increase as the dose gets higher, but it's not that far off if you think in terms of percentages of the dose. At 10 units, we go to 1 unit increases, unless you are tweaking a dose with pretty good numbers. But of course ECID, some cats are sensitive to smaller changes, some not. You have heard the phrase Know Thy Cat, well, it's even more true for a high dose cat. You also don't want to sit on a dose any length of time, if it's not getting you numbers you want. There are times the acro tumour can grow and insulin needs are too, and it's like you are competing with that growth to get back to good numbers. You have seen that already. The tumour can shrink, and it that is happening, you need to be on your toes with decreases. And be aware of the larger depot, with possibly reduced doses following a reduction to drain the depot. Again, ECID. You will do lots of experimenting to learn what works for Jimmy..
R is something used by many, but again nothing written as it's very ECID. We suggest you "book" a time with an experienced person who has used R, who can sit with you the first few times you use it. We start with a small dose at the right time, and work our way up. I say right time, cause it's also important to know when not to use R.
FWIW - radiation treatment brought a much better QOL for Neko. At the time, it was the only treatment option available to us at that time. But the majority of acrokitties are not treated, other than with appropriate doses of insulin. You do want to try to keep him under renal threshold as mush as possible, as acromegaly is hard on kidneys.
Which also brings up the topic of what to look for. Learn what can happen with soft tissue and bony growth, not all cats see the same things happen, but it's good to be aware of them. Neko saved a tooth because the dental vet found soft tissue growth in her mouth, instead of what looked at first to be a bad tooth. Have the vet keep an ear out for heart murmurs, as heart issues can sneak up on you, but can be treated with meds.
Keep asking questions.
