It's not uncommon for a kitty to go from one bounce to the next for a while. Like weeks. It depends on how long they have been sitting in high numbers before they began insulin and started getting back into normal range again. The body has to hit green enough times, and hopefully stay there for enough hours, that the body "remembers" that this is normal. As you go through this process, the bounces will lessen, both in duration and in intensity. Instead of lasting 3 days, he'll move to having a bounce last 2 days, for example. Instead of getting to 500, he'll only bounce to 200. The "cure" for bouncing is to "keep showing him green." It works, it's just a process that takes time.
The good news is that when he's in a bounce, you get to have a "save a strip" cycle. Stop testing now til pmps. It's likely this bounce will last at least 2 days, so for the next couple of days test minimally. I usually tested at preshot and one test in between until I caught a low yellow, or I expected the bounce to clear. Last night was so on schedule, which was why I was able to predict it. It was slightly less than 3 days, so I'd expect this next bounce to last at least 2ish. Starting Thursday morning I'd be watching for signs of it clearing.
Of course saying that doesn't mean it will happen - that's just what MOST cats do. Cats are notoriously unpredictable, but it gives you an idea of what to watch for. And enjoy the break. Sleep well tonight.