It could he from the gravy food last night
When I had to feed gravy to George, we would get soupy poo the next day, with George it didn't last long. He'd get back to normal within 24hrs.
I know that some other folk find that their kitties are quite sensitive to the gravy foods, so instead of using gravy they would simply add honey to their regular food, to boost the carb content and avoid the tummy sensitivity issues.
Hope Sprocket gets back to normal soon. Great that there are no ketones.
I know that you found last night scary, but really those were great normal numbers (bear in mind the normal range for a cat is 50-80 when using a human meter), he was a long way off from being in the danger zone.
Personally when I have been in similar situation with similar numbers, and if I was around to monitor, I would probably have tried to avoid using the higher carb when you did, I'm not criticizing, just an observation for your consideration. With time and experience you will learn to get accustomed to seeing and dealing with those green numbers, they are damn scary when we are not used to seeing them, the first few times George hit green, heck even a low blue, I was shaking like a leaf, keep at the back of your mind that those greens are the ultimate goal if you want to try and achieve regulation for Sprocket. I think that it's possibility that Sprocket shot up to blue and then Yellow because of all the carbs/food early on in the cycle, there may also be a little bit of bounce in there too. The goal is to get him to drop and surf in those greens and low blues, sometimes it needs a gentler touch, if when he gets there, you wallup him with HC he's not likely to stay there for long, that's why we don't normally suggest using HC to steer when they are above 50.
It's a difficult one to get your head round, had you used LC say the 7%, he wouldn't have necessarily, dived on you, but he might have cruised along in the blue greens for longer in the cycle, as I've already said, that's the goal for regulation, the more time he spends in that range the less diving and bouncing he will do, and the easier (on our nerves) it becomes to manage.
As for why the cycle panned out as it did, who knows, certainly, he gave you the heads up with that falling PS, the numbers were heading down, so you did exactly the right thing by getting the +1, I thought the choice of 7% at that point was a good one, as he was remaining level at that +2.2 I might have stuck with just the 7% rather than the 13%, (which by the way is MC) (and as you mixed it with equal amounts of 7% that made that snack overall 10%)(HC is over 15%), by +3.5, as you are moving along in the cycle you dropped back to 7% that was a better choice (remember that as you move along in the cycle the lighter the touch with the steering, so you could have gone with lower carb)
You might feel that if you made the lower carb choices above that he may have dropped like a stone, I don't have a crystal ball, but what has been my experience when I experimented with steering with George, and of course ECID, is that when I hit him with too many carbs or too much food overall, it would tend to shorten the time he spent in the lower range and cause him to shoot up earlier, overtime I learnt to have a lighter hand, and I think that helped him get regulated by getting him to spend more time in the blue/greens, and eventually getting the yellows to disappear altogether. If you look at his ss, I made notes of what I fed and when, and there are also links to the condo of the day, so you can see what my thought process was on a given day.
My intention with what I have written above is to do, what I used to do after I had a scary/unusual cycle, after the dust had settled and the nerves/anxiety had passed, I would look back at the cycle, and say to myself (I would also ask in George's Condo), what could I have done different, what worked, what didn't, what could I try next time to achieve the outcome I wanted. Anyways I hope you take it in the spirit it is intended.
I kept similar feedings when we moved to Levemir, because Neko was resistent to food changes.
Apologies if it doesn't.