The dosing protocols are guidelines, not hard and fast rules, because ECID. Every Cat is Different. You need to find out how YOUR cat reacts to the insulin, when the onset is, how low a particular dose brings down the BG numbers at nadir, how long the duration is for a particular dose, what reaction your cat has to the different food options (LC, MC, HC).
Tom was diagnosed back in November 2019, so the "holding the dose for 3-5 days when starting" does not apply. You started Tom on insulin months ago, so the protocol sections that apply are the ones that talk about adjusting based on the nadirs.
The dosing recommendations are different, depending on which protocol you are using. We need to know which protocol you have chosen, so we can help you to the best of our abilities. When to skip, when to stall, when to hold the dose, when to increase or decrease the dose are all dependent on the dosing protocol you are using. Those protocols were developed from hundreds and hundreds of cats, by many experienced members of the message board, after following many cats in their diabetic journeys over the last 3 decades, and reading hundreds of spreadsheets, and they were updated in February 2020.
Why does it make a difference between 3 and 7 days you ask? Well, if you cat has ever had ketones or DKA, they are more prone to that condition occurring again. Holding the dose for 7 days with a cat in that situation could be too long. A cat that drops really low, very quickly and early in the cycle, then changing the dpse every 3 days may be too soon. They need time to adjust to the dose changes. ECID Every Cat is Different, Every Caregiver is Different, Every Cycle is Different.
"Know Thy Cat."
You can also change the dosing protocol you are using. You are not "locked in" to a single protocol. MPM is a more aggressive dosing method, since it let's the nadirs drop to 50 before doing a dose reduction. Since Tom is eating only low carb canned food, you are able to choose either SLGS or MPM. If there was still dry food in the picture, then only the SLGS protocol could be used. That is because dry food takes too long to have an effect on the BG levels, if they drop really low (<50 mg/dL)
Yes, you are fine holding the dose for a few days, to see how things go on the new higher dose. But the MPM protocol under the section "Increasing the Dose" is looking at a nadir of >200 and saying a 0.5U increase is warranted.
I tell folks that they know their cat better than we ever will. They also know their schedules and life responsibilities better than we ever will.
You hold the syringe, the final decisions are always yours.