If you were to look at any of the others with acro cats, their ss will show you plenty of blues that turn out to be false hopes. Quite often, it's like a tug of war; increase the dose and see a reaction, but then the numbers pull back again.... resistance.
The cats with IAA have a wild ride with their dips into lower numbers only to bounce back up.
A mix of IAA and acro is yet another combo to see.
People are recognizing the signs for resistance in other cats, and those cats are getting tested sooner than they ever have before, and it's for that reason, you are not seeing the very advanced signs and high IGF-1 numbers. It's important to keep in mind that the test result numbers are just a snapshot; they don't stay put and you can test later on and likely get a higher number. Some cats who have SRT still test and get positive numbers, yet are OTJ. The numbers are not the entire picture, the deciding factor.
My Shadoe did not look acro, had NO visible signs, have a tiny body and very small paws, and no wideness to her head at all, and she was female. She had no belly, but was up to 9u BID by the time I convince the vet I wanted the 2 tests done. By the time we got the result of 120 for acro, we were up to 14u BID, and she still did not look acro, plus the vet doubted the test result.
Fast forward from 2010 to 2011, and Shadoe's head looked broader, rounder, and she became almost all pot belly on tiny legs, with a round head. It's funny what a bit of time can make when it comes to seeing the signs develop.
Because the resistance is being 'recognized' sooner by others who have lived it, cats are being tested near the front end of the condition, as it's developing, instead of how it must have been in the past where vets may likely have not known about the tests, thought the condition was too rare, and many cats were likely pts because they were told 'there is nothing else we can do.'
I was told that I was overdosing my Shadoe, and I was told the same with Oliver after I adopted him, and made to restart to 1u because of possible rebound.
I ended up with two acro cats, so either I need to buy more lottery tickets, or else acromegaly/ insulin resistance is not as rare as people think.
It's wonderful you are getting the tests so that you can have an explanation for what's going on, or you can eliminate a couple possible conditions.