Hi Sean,
Sorry no-ones come back to you, but it shows how small a group we are relatively, and how different everybodies type3 experiences are. When I first started on insulin, my diabetic nurse specialist for the whole county told me how difficult she found it to treat us type3s.
In case you haven't been told, not only do our damaged pancreases (pancreatti?) not produce insulin properly, but many of them don't produce stomach enzymes properly either, so food absorbtion can be very variable. So a personal question that you don't need to answer publicly here - does your poo float, stick to the pan and smell awful, and does it take quite a few flushes to get it down the bog? If so that's called steatorrhea, and it's likely that you have stomach enzyme problems.
You don't say anything about a sensor (Libra or Dexcom etc), so I assume you are finger-prick testing. That's fine as guide, but doesn't show the full picture like a sensor does. So you've compared a heavy mid-day meal with quick action insulin to a hefty intake of choco digestives and asked why the digestives (without insulin?) went higher. Every t3 person's body reacts differently to different food types, but as a rough guide there are very quick acting things like sugary things, and slower acting things like carbs. So you need to prick-test fairly often to get a better picture of your own body reactions.
I'm not qualified to give advice, but I wonder if you turned into a 'nibbler', so little and often, you might find things a bit better, with less 'highs' but a slightly higher 'normal'.
