I was wondering where the 31 was on your sheet - I am in Canada too and regularly go back and forth between both units of measurement quite happily now.
I guess its up to you what your goals are, if you want to better regulate Sam, or even get into remission ( and time is running out fast for that!) then I think you need to make some changes. He doesnt look well regulated and he is running out of time to go into remission.
We can prove scientifically that 84% of cats go into remission in the first six months with a low carb diet, a good insulin like lantus, and frequent home testing for dose change purposes. But after that time remission becomes unlikely.
So I am thinking you should test more. It doesnt do any harm at all , so you arent doing any wrong by going against what the vets said, and in fact you may do good as you might discover some stuff that will allow you to regulate him better!!!. And I do think we can get him regulated better with more testing as I suggested. Or we may find an underlying issue here which is also important to identify.
3-4 tests a day. Thats all it would take. 2 preshot, 1 before bed. and a spot check every day or two mid cycle. But its up to you.
Wendy