By that method I’d never be in ketosis. In ketosis, out of ketosis, low ketones, high ketones, PSMF, actual fast, zero perceivable difference, only time I’d (assume based on previously doing it) would be if I were to do a multi day fast and had off the charts ketones.
Last week was a quick fat loss for me, so instead of my normal TKD/CKD I went back to standard keto, no problems, no energy issues, no keto flu, last night did a carb refeed for the gym this morning and again, aside from looking better in a t-shirt again, everythings normal. I take in fuel, and I burn it without issue. I think a lot of “feeling” ketosis is a novelty thing when it’s new and you’re used to feeling a certain way, after a while it’s just the baseline again. Even when I was doing standard keto all the time and actually checking them, my ketones were never above 0.4 most of the time unless I was fasting.
I think your results are pretty specific to people who (may) always have really high ketones, which I did in the beginning, but after years of eating this way that usually doesn’t keep up. I do get the nootropic effect when taking exogenous ketones so for me that’s the only time I feel it.