Hi Cindie and welcome to you and Gryphon from another Canuck in Ontario. What a handsome little man you have there!
You and Gryphon have really been having a time of it recently and with the Acro to deal with....quite the situation. I am the mother of a high dose little girl but her problem was IAA (Immune Auto Antibodies). Like you, my vet was very supportive but admitted to never having dealt with the condition. This board gave me the knowledge and support to get my girl under control and eventually into remission which surprised the daylights out of me and everyone else but especially my vet!
I see from one of your other posts that your vet has discussed using Lantus along with Regular insulin to try to get Gryphon's numbers under control. If you decide to switch insulin, if I were you, I'd definitely try Levemir instead of Lantus. I had to switch to Levemir because Lantus was causing uncomfortable injections due to it's acidic composition once I got to a dose of around 6 or 7u twice daily. While Gryphon may not be noticing it yet, there is the possibility that if you have to increase the dose any further, he too might start noticing the injections a lot more and goodness knows he doesn't need any more unpleasant medical symptoms to contend with. Not only that, but if Lantus didn't work before, why not change it up completely and you can still use regular insulin with the Levemir if that is the plan you choose to go forward with.
As others have mentioned, the problem with Caninsulin is the steep drops in BG it causes which often lead to bounces and that makes regulating any kitty a bit harder in my opinion. Add to that the Acro which makes regulation more challenging due to waxing and waning hormonal changes and the fact that Caninsulin often doesn't last through the entire 12 hour cycle, the fight against high BG will be even more difficult than if you switch to a longer lasting insulin.
In the meantime, we're more than happy to help you out with the Caninsulin. I see Gryphon dropped a bit too low on the 8u dose and while that may have just been a hiccup due to a hormonal blip in his system, it may signify the dose is a bit high so I would back the dose off a smidge to 7.5u to keep him safe right now. You can always increase again later if need be.
Where in Ontario are you located? I'm in the west end of Toronto.