the ideal numbers for a cat with acro is low enough that you don't have organ damage ~225ish or less, and high enough that they won't become hypoglycemic.
there's a couple of considerations. one is that the bigger the dose, the bigger the shed. you don't want to get into a situation where you're giving carbs trying to counter low numbers and the shed is still giving insulin to pull the numbers down. the tumor itself that causes acromegaly is classified as "pulsative" meaning it pulses. meaning that it can shut off its hormone production at any time. if you've shot a large dose and suddenly the hormones disappear that are preventing the insulin from getting into the cells - well, now you've got a really serious situation.
honestly though, even at 7 units, if suddenly all of that insulin were received into the cells, i can't imagine it wouldn't be a problem. we just hope that doesn't happen.
at the same time, a cat doesn't suddenly change the way its body responds to high carbs. punkin is relatively responsive - where you all give a teaspoon of high carb gravy, i give about 1/4 can to him. that just makes him a very happy kitter! :lol: and he always has room for more! so i feel pretty confident about his responsiveness and not worried about that part.
based upon my experience with punkin, i'm also not worried about the tumor suddenly shutting off. we're seeing parts of it die off and that's the reason for his dose decrease already. so what i really want is numbers low enough that his kidneys and pancreas, especially, aren't damaged.
if a cat has too many high numbers the pancreas beta cells can be damaged and might or might not recover if he does go off of insulin.
there's no exact science about it. in general the range i'm aiming for is 100-150. but ya get what ya get, as we all know. ;-)