Neko had both acromegaly and IAA. I didn't use R until after her antibodies broke just under 9 units. Basically at the time there wasn't anyone on board here familiar with using it in a high dose cat and willing/able to teach. So yes, you can break the resistance without R. However, I have also seen IAA/acro cats need to get north of 50 units of insulin to break through, even more if you consider the R dose on top. ECID - and high dose condition cats are even more different. I have also seen acromegaly only cats need north of 30 units to break the acro resistance. It may be the tumour, not the IAA that is your enemy at this point.
We do recommend that people get an R teaching buddy to "sit" with them the first few times they try R. There are a few key things to learn about when, and more importantly, when not to dose R with the basal insulin.
Remind me again, are you using Lantus? It's helpful to put a few things in your signature, such as the link to your spreadsheet, date of diagnosis, insulin and dosing method being used, type of diet, any other medical conditions. Some people see an antibody response if they switch to Levemir. Though with 6 weeks left, I wouldn't bother with the change at this point.
One more thing, Neko's IAA basically broke around SRT time. I'm guessing the radiation therapy on her tumour started it. If Sophie doesn't need exogenous insulin after surgery, she won't have IAA.
