I'm still concerned the dose is a little high. That's such a steep drop, and you did see some better PSs a little while ago when you first tried lowered doses. I think you may be in the same boat again, and need to lower again. The thing is you can't increase the dose when you see a red or black # - if that is rebound, then you are adding to it with the higher shot, and perpetuating the wide swings.
I would try lowering the dose a little bit, and ride out a couple high PSs w/o increasing the dose, and see if the PSs come down on their own.
If it doesn't work in a day or two, you can always raise the dose back up. Remember a few weeks ago you were getting these same kinds of numbers on a full unit more than you are giving now. You reduced the dose, got better PSs, and now are back to the wide swings, even with a lot less insulin. So that's where I'm thinking if you try another round of reducing, you might find the PSs settle down and you can still get good results on an even lower dose.