I would try 2 more days with no shots and see how he does. Today looks perfect, the days before that...eh, little more blue than I'd like. We like to see nearly all green numbers for 2 weeks with no insulin before calling it remission. But since you have Caninsulin, he is not giving you any room to give any insulin at all. Not safe to give insulin at this point.
I'm hoping the last 2 days of blues/yellows were just his body trying to re-equilibrate to no insulin.
So tag me in 2 days, keep testing like you are. But if you see anything yellow or above let us know (but do not give insulin, wait for advice). Please check ketones daily just in case, going from 1U to none is a big difference.
If he's still nearly all green the next two days, we'll do what's called an OTJ trial - 2 weeks with no insulin, but still monitoring BG
Fingers crossed!