Some who eat LCHF don't necessarily transition to how we have recently defined dietary ketosis in terms of blood ketone measurement - >0.5mmol and <5.0mmol.

Some, I was one, who eat LCHF may not be in ketosis which is the indicator that your body favors fat over glucose for fuel. I was eating LCHF, and I suspect some influence of carbs and protein kept me from getting there. Some can't get to ketosis unless they strictly limit carb intake well below the guidelines of <50g per day. I benefited from LCHF without being in ketosis, but I realized more benefits when I established ketosis as a goal. I believe many who started Atkins years ago went out of ketosis after induction due to eating more protein than fat and had a glucose source from the protein via gluconeogenesis. I've learned a lot since then.