Rats, I was really hoping for a 150+, lol.
OK, Wynk has told you twice in the past three days that he needs less insulin. The important part, to me, is how he has shown you this. It is NOT because his cycle ran "too long" and gave you a non-shootable number at PMPS. Long cycles are a GOOD THING, and if every cat had long cycles, there would be a lot more cats going OTJ than there are. Long cycles, caryover, and overlap are all your best friends, no matter what anybody thinks. You just have to know what to do with them when you see them happen.
The reason that Wynk needs less insulin is because he dropped to 90, and he dropped to 64 at nadir. On your meter, both of those numbers scream "less is best", no matter what his preshots were, and no matter when the "nadir" happened in the cycle. What Wynk might also be telling you is that he has decided to become a "late nadir kitty". Unusual, but not unprecedented. Ask Bobbie what dealing with a late nadir kitty is all about.

Heck, there's a kitty named Gracie who sadly crossed the bridge recently that nadired at +14 regularly. Think about how much fun that was to wrap your head around!
Wynk's drops have both happened on a dose of 2.4u, once on a AMPS of 390, once on an AMPS of 456. He's saying "Mom, I'm done with a 2.4u dose, okay?" Of course, all of the protocols are set up to make dose adjustments of .25u or .5u, but since you are using U100 syringes and the conversion chart, none of your doses ends in an odd digit. So you'd have to think in terms of .2, .4 or .6 when increasing or decreasing. Personally, in this case, I'd go with a reduction of .4u
I do, however, agree in priciple with what Robin said earlier:
He may be one of those kitties whose body reacts better if you find his "sweet spot" dose and hold it for several cycles.
The issue there is "what dose"? I think 2.0u is good for a PS number above say 325, but what if he throws a 275 or a 225 at you? In that case, 2.0 might be too much. That where instinct and gut feelings come into play. You do have a good bit of data, but the big factor in the last two weeks is that you went with "portion control" (good idea), so that makes the data prior to that a little less useful as far as determining a good dose for various preshot ranges.
If you want to try using a scale, taking Sue's scale from above:
200-250 - 2.0 u
250-350. - 2.2 u
350+ - 2.4 u
and adjusting like so: (this assumes a no-shot cutoff of 150) ?
150 - 225 1.0u
225 - 325 1.4u or 1.6u
325+ 2.0u