I really don't get much attention from the experts on this site so what is the point?
A few tips to make it easier for us to help you. First, you have the question mark icon up so we know you are looking for answers. That is good. You also have a paraphrase of a question. That is also good. BTW, many people here could stop by and answer about nadirs. However, no where in any of your entries today is there any detail about your question. The answer to "when is a nadir" - is whenever the cat has her lowest number. I'm not being flippant. On Lantus, Neko's nadir was anywhere from +3.5 to +13. Some cat have more variable nadirs than others. Other things can change the insulin action, like bounces, insulin absorption, possibly shot location, food, any life stressors, or just plain because they are a cat. There isn't always an exact answer for every question.
Side note: your posts tend to have a lot of chatter. I do try to read most of what is written before I respond, but sometimes that's just more work than I feel like doing, cause this isn't the only thing I do on this site. Our previous moderator hardly stopped and posted on anyone, unless she felt it was something she was uniquely capable of responding or some key information was missing. I tend to the same. There are many people who can answer questions about nadirs - no reason you need a moderator to respond. There are no experts here, the majority of posters are not vets, just people with varying levels of FD experience.
Plus, it's the weekend. Always less traffic then.
You don't increase because a cat bounces. You increase if she needs more insulin based on her nadirs.
As for the comment about being frustrated, scroll back a month on the spreadsheet. She is doing so much better now than she was then.