This post that is on the Lantus board is a helpful one to bookmark as it addresses
how to handle low numbers. The post was initially written for Lantus users but the principles are the same.
There are a couple of things to consider. How you intervene can depend on when in the cycle the drop in numbers is occurring. Earlier in the cycle (i.e., before nadir) may require a more aggressive intervention than numbers that are dropping later in the cycle. The speed of the drop can also dictate how you intervene (e.g., with high carb food vs Karo).
In KitKat's case today, the drop started fairly early. (And you did a great job of staying on top of the drop.) I generally coach people to use a few teaspoons of high carb food initially to try to get their cat "surfing" in lower numbers. Remember, normal numbers are good! The more time your at spends in normal numbers, the more his body will acclimate to that range and his liver and pancreas will stop panicking. What you're seeing is a lovely surf!
You also don't want to overdo the high carb. We've had members come close to drowning their cat in Karo or give their cat a can of high carb food all at once. Spread it out. Use a small amount, test, and repeat as you need to.
I also suggest testing more often. A lot can happen in an hour and frequent testing gives you more control over steering the drop in numbers. High carb can wear off and numbers may drop back down. You don't want to let the possible momentum of a fast drop get ahead of you. My cat had a tendency to have numbers drop early and drop fast. I would routinely test early in the cycle and if numbers were dropping, I would test at least every half hour. You can look at Gabby's spreadsheet to get a feel for what I did and how I stacked the numbers in the cell.
I don't know that you gave too much insulin. I tend to think it's a bit of a guessing game to try and predict what the numbers will do. It looks like the numbers were pretty flat between your PM +10 and AMPS. I would have encouraged you to shoot your full dose. There's no way to know for sure how your cat will respond.
Also, your spreadsheet says you're following MPM. Your signature says SLGS. KitKat gets a dose reduction if you're following SLGS. He doesn't if you're following MPM.