I'm sorry you guys are having such a bad time. I think you're right on with the explanation about her BGs, though. I think it's as simple as a failed reduction. She was doing ok at 1.0u and when she got a reduction, she lost the green numbers. You've gone back up in dose so hopefully, she'll get back on the green track before too long. It looks like tonight she's starting in yellow and maybe she's leaving the pink numbers behind.
The beauty of this site is the wealth of experience from a variety of people - sometimes it can be hard to figure out how to move ahead when information conflicts. I say that because I'm about to give conflicting experience on the cerenia, hahahahaha. I gave it to punkin in a duck and pea pill pocket and it definitely was effective. I liked using it a lot. Perhaps it reduces its efficacy some, but it may be that in spite of that, it's still effective. It was for punkin.
Try not to obsess about the dental. You are doing a heroic job with Noodle, far more than many people would do for their cat. Just do the dental when you can and know you're doing your best for her in the meantime.