Hi there! I haven't been following along lately, but Gator asked if I could stop by ... so here I am!
My take is you were getting intermittently good results back around 10/17 and the days around then. Then started getting some improvement maybe (? a little puzzled why such good results on 10/30...?), but then started losing ground around 11/6 on the 3u, and then it looks to me like his body has been staying ahead of the dose since then.
My experience with Bix has been that it takes less insulin to keep him in good #s than it does to get there - I suspect it's because of a sputtering pancreas, which Klinger may or may not have. With Bix, if he gets up into pinks it can take a few cycles and higher doses needed to bring him back down, whereas if he stays in blues & a few yellows, a smaller dose is needed to keep things steady. I don't exactly mean sliding scale, though it's probably semantics, more that my sense is they can get sort-of stuck in higher #s (my read is their pancreas may have been helping at lower #s, and then goes back to sleep in the higher #s).
If that read is correct, I would expect you will see a breakthrough pretty soon, since you are at about the dose that seemed to breakthrough fairly well before. And then you may find a bit of a dose reduction path is needed, possibly landing you back around the 3.2 zone and still seeing decent #s. But if Klinger's patterns are like Bix's, I'd say that once you've lost ground, a good working dose is useless - you have to go back up to the breakthrough dose to get back to decent #s.
I'm not sure that made sense, what I'm trying to say is that (if my read is right) the #s make sense to me as 3.6 you got in good #s, then only needed 3.2ish to hold them, then got out of good #s and are losing ground pancreas-wise, therefore need to go back up to the 3.6 to get back to the good #s (and then if you are lucky will be able to come back down to 3.2 or so).
If you don't see better #s and start getting to doses over 4u w/no sign of better #s, then I'd say something else (?) may be going on.
I don't see a rebound pattern. That 566 on 11/28 is wonky, but everything else I see is pretty much U-curve, which is what you want.
If you have a desire to try early shooting that's one option - it is pretty daunting though, so I wouldn't push that on anyone. It does look like (past few days overall high #s notwithstanding) he hits the high #s by +12, so on a day when you do get good blue #s, shooting at something like +10 or +11 to head off the higher #s with some cats really works wonders. It's not too useful though if that means you can't shoot til +13 or +14 on the next cycle - it works best if you can take a long weekend or something and stay on top of the #s. It's hard for me to tell what in Klinger's #s might be liver training, and what is just that he throws high #s and needs a decent dose of insulin to counteract that.
On the dental front, when Bix had his teeth done his #s ran higher for a few days, and then after that seemed to go back to what they had been. He had several teeth out and possible infection/ABS, though they couldn't say for sure if he actually had an infection or not, so if not, that could explain the lack of change in his #s.