You may find it helpful to do some behavior training outside of the testing stuff.
Decide on a behavior you want to encourage - something small, like "Up" when you want him to get up on something or "Down" if you want him off something.
Find a reward he likes a lot - sometimes it is food, but it could be a particular toy, or being brushed, and so on.
Training sessions should be short and frequent. Cats learn well with repetition.
Lead him into doing the behavior you want to reward, say the command which goes with it, and give the reward.
Ex. You want him to jump up on something, say "Up", lead him with the reward to jump up, and reward.
You might work on Up and Down, Come, or any other behavior you want to encourage.
Eventually, you might add "Test" with small steps shaping the behavior slowly.
At first, that may mean you just massage the head and ears, and treat.
Then you might add in holding a specific ear and treat.
Add in putting on some Neosporin ointment with pain relief and treat.
Wiping off the Neosporin and treat.
Testing and treat.
Meanwhile, check the Secondary Monitoring Tools in my signature link for some additional tactics for assessing him. Ketone testing in particular, is important, as high ketones may indicate diabetic ketoacidosis (DKA), a complication of diabetes which can be costly to treat and is potentially fatal.
