Awesome seeing those blues today!
Could also be a bounce from the fast drop. Some kitties bounce when they drop more than 50 points an hour. The other thing you are likely seeing is the effect of the high carb food. I think you would have been fine with continuing to feed medium carb. Usually we'll save high carb food for the greens. By feeding high carb, you put the brakes on the insulin action, shortening the duration and as a result you get those high preshots. High preshots can mean big drops = more bouncing.
By the way, you might want to put notes in the Remarks field about what food you gave when. So something like 2 tsp HC@+3 will help you keep track of what you've fed him. If you do go the path of steering with food, it's good to have a record of what worked (or didn't) previously.
I too liked the history of Shoes. I have a friend who does cat rescue from the local race track. People keep on thinking a barn is a good place to dump a cat - and there are coyotes living in the infield.
Another comment on yesterday's condo - it's really hard to get a cat to stay flat, below renal threshold and in sensible numbers, without seeing green. Neko was a very bouncy kitty when I started - I used to call her the Rainbow Queen. I've found over time that Neko will stay mostly under renal threshold, if she's getting a dose that gets her nadirs down to the 70's or 80's. Those numbers of course on my human meter so a little higher on the AT.