I may be on your side in this discussion, based mostly upon my one anecdotal observation and one clinical.
Clinical: The Paleolithic Ketogenic Diet promoted by PaleoMedicin, keeps daily food intake low (somewhere around 0.6 kg of meat a day) which means protein intake is also pretty low. They prescribe this to keep people in therapeutic ketosis which means higher ketones than those of us doing more of a “nutritional ketosis” as coined by Dr. Stephen Phinney.
Anecdotal: For the first few years I started eating this way, I tracked my morning ketones and blood sugar daily. I did notice that in the mornings, my morning blood glucose trended lower, and ketones higher when I ate less protein and more fat. The problem for me was that having lower protein resulted in more hunger. Since I don’t have metabolic disorder or some other health problem requiring therapeutic levels of ketones, I’d rather have the extra protein.
Also, continuing with my own anecdote, I did find, however, that my hair and fingernails did not like the lower amount of protein. About two years ago, I got into strength training, and upped my protein intake to about 120 g per day. My hair health and fingernail health improved dramatically. I’m vain; I’ll take a much nicer head of hair and lower ketones.