I was looking for a bit of history on Trey and couldn't track the information down so I'm going to make a few assumptions. Since Trey is newly diagnosed (8/12), I'm guessing you've been reading like crazy and switched his diet to a low carb, raw food diet vs. whatever he was eating previously. That's likely why. you're seeing the change from numbers in the reds and blacks to blues and greens.
On a day like 8/25, if you get a number that seems out of sync (e.g., the 413 at +6), it's helpful to re-test. That 413 was a huge jump from AMPS and given the PMPS number, it definitely seems wacky. It may have been genuine but it also could have been a bad test.
For the amount you're able to test, you could consider TR. It's a more aggressive approach but it's where we have the largest amount of scientific evidence for cats getting into remission. It completely depends on your comfort level but it's worth consideration (IMHO).
Prednisolone is a steroid. For many, if not most cats, steroids raise BG numbers. In fact, many cats develop diabetes as a result of being prescribed a steroid. If today is Trey's last day on pred, please be attentive to testing. His numbers may drop further. What what he being prescribed pred for?
Depending on what you mean by, "...testing on the low side", you may not want to wait an hour or two to re-test. My kitty was one whose numbers could drop fast. You are welcome to look at Gabby's SS to see how I would test. There are also instructions for
managing low numbers in the stickies.