Am I right in thinking that as Caninsulin is an in/out insulin, I adjust the dose according to preshots, as have data knowing how he should react?
There certainly are people who use sliding scale with Caninsulin. And I did that with Bertie.
But there are also cats that generally do better on a fixed dose.
And there are differing schools of thought as to whether or not a dose needs to be maintained for a length of time so it can 'settle'. (My own vet thinks a dose needs time to settle.)
Confusing isn't it?

I guess it probably depends on what works best for the individual cat.
Cats with variable BG numbers can benefit from sliding scale dosage. That was why I tried it in the first instance. Bertie's numbers were all over the place.
(But I agree with
@Critter Mom that it could be helpful to try to ensure that the carb level of your kitty's food is fairly consistent so that you can try to have some control over that particular variable.)
Sue, did you actually give Romulus 2 units last night at a preshot of 8.1? (Just wondering if there's an error in that data..?)
If you did give the 2 units at 8.1 then two things immediately come to mind. Firstly, that pre-shot number was too low (it was a normal blood glucose number on an Alphatrak). And secondly, it was a
falling number: There was no indication that the blood glucose was actually
rising. I managed to give Bertie his first ever hypo by shooting a falling number, so I'm kind of cautious about that kind of thing!
It must be tough going managing TWO diabetic kitties.
Huge hugs to you for all that you're doing for them.
Eliz