That's a wonderful "Whole Cat Report" Cindi.

Often times, we see big improvements in the clinical symptoms before the BG levels look really good.
"Clearing" a bounce basically means that the steep spike in BG due to the release of glucose comes down quickly. A cat can also release counter-regulatory hormones that cause temporary insulin resistance, meaning that as a self-protective measure (either "legit" self-protection due to a number that's too low, or "panicking" due to healthy numbers that they simply aren't used to), those hormones prevent the insulin from really lowering the BG. This can look like high numbers that hang around for a few hours and don't seem to budge downwards even with insulin, or the bounces can even last for a whole cycle, where the numbers are high and flat despite insulin. My guy Eddie would have both high pre-shot "bounces" and high flat cycles that were bounces. "Liver training" as used around here, basically just refers to "aiming" for good numbers at nadir and ignoring the bounces, with the idea that eventually the kitty gets used to those healthy numbers and stops bouncing. If the bounce is due to a number that's
too low, you will want to reduce, but if you follow the "liver training" school of thought, you don't reduce simply because kitty is bouncing. That said, there's no hard and fast rule here.
Particularly since Merlin is on such a small dose, you can certainly experiment with continuing to shoot for nadirs that are in the healthy range, despite his bouncing, and see if his bounces will settle down, or you could experiment with a decrease and see if his pre-shots come down a bit. There's not a specific time frame to try one approach or another. With ProZinc the nice thing is, you can tweak as needed.
It's totally up to you if you'd like to try a reduction experiment. With my guy Eddie, I generally followed the "liver training" approach, but experimented a couple times with trying to back off the dose a bit with varying degrees of success. Merlin is getting nice nadirs with the current scale you're shooting, but if he continues to bounce and bounce and bounce, you might want to consider backing off a bit. What are you thinking?