Hello and welcome. I too had a kitty who was a "big gulper". She needed more insulin due to have two secondary endocrine conditions, IAA (insulin auto antibodies) and acromegaly. Think of the former like the body reacting to the injected insulin like a foreign body or allergy. The antibodies grab onto the injected insulin and make it unavailable, until they die and release it. The latter is caused by a benign pituitary tumour that sends out excess growth hormone that ultimately causes the diabetes. One in four diabetic cats has acromegaly, though not all get to higher doses. However, once a cat gets to 6 units by safe increases, we suggest people test for those two conditions and the chances are one or the other is positive.
That brings up the topic of how fast and how large the increases have been to date. So, let's start by hanging onto this 6 units dose at least six cycles (three days) and see what happens when the depot is full. Of course, if Pumpkin goes low we'd decrease. For this little experiment, I'd like you to get the preshot test and at least one other per cycle. You've been doing a good job of mostly doing that so far. Keep posting every day, and I'll try to keep an eye on you. If a kitty is over dosed, we should be able to see the results in those three days. If you need to increase, it would be by 0.5 units. Do you have 1/2 unit marked syringes?
By the way, one of the reason his numbers seem higher than others is that you are using the AT, which reads higher in higher numbers. The majority of us use human meters which read lower at those high numbers.