Ketones are only going to be present if you are exceptionally bad (very high carb diet) or exceptionally good (very low carb diet) at managing your blood sugar. It's not going to be terribly useful for your average diabetic who has fairly good control over their blood sugars.
> your average diabetic who has fairly good control over their blood sugars
I think it's huge for diabetics. It's a mental toll for them. They hate having to constantly prick themselves to take readings. It's awkward, inconvenient and you have to do it multiple times to be sure you got a good reading. And worse of all, it's possible to forget to take a reading when you need to.
Which makes me think the market for these is diet-focused folk. Get the FDA to clear it on medical grounds for a specific usecase then sell it more broadly.
This already happens with CGMs. The bulk of the sales is with people who want them for lifestyle monitoring even though they're only medically cleared for diabetes use.
A measure which acts as a high and a low pass filter on a band of less risk which can be monitored by other means, or subject to improvements on measurements and narrow the central zone?
Sounds bloody useful to me.