Ok so I've come back from the vet, he recommended me to increase the dosage to 2.5UI twice a day to see how it's responding, also, he recommended me to divide his food in 4 meals / day, one every 4 hours.
I think that's good news! Did the vet mention anything about treating the pancreatitis?
You've mentioned that Pisi doesn't act like her (is it a girl's name? I just assumed, sorry!) BG is high. I don't know how common it is for cats to show behavioral changes connected to their BG number, but with my cat you wouldn't be able to tell the difference. The only sign I've ever noticed and which led to me taking her to the vet was extreme thirst. Other than that, her appetite, playfulness etc. are the same no matter what her BG is.
Yeah, I see why you don't recommend shooting below 200, I'll see what to do, I have to call the vet today anyway to talk about the changes over the weekend since we increased the dosage to 3U/2x day, I'm prepared for the hypo as well, I have glucose prepared and I'm checking his BG frequently after giving the shot to prevent it to drop way too low, but wasn't the case till today, when it's the first time in the last month when I'm seeing values under 500 in the morning, so he might respond well to 3UOn FDMB, we don't decide on what dose to give based on the preshot number, but rather the nadir, or how low the dose takes the cat. More information is in this post which describes how we do dosing: BEGINNER'S GUIDE TO CANINSULIN/VETSULIN For people relatively new to feline diabetes, we suggest not shooting if below 200 at preshot.