I am aware of the "eating wins races" strategy for endurance sports.

Glucose and ketone monitoring seems a natural, more precise extension of that strategy. Isn't the point of carb-cramming to get more glucose into your blood stream, where your muscles can convert that into forward motion?

Yes. But you don't need to monitor glucose levels to do this. Because it's well known you can productively use as much as you could manage to consume (without vomiting). So all the device will ever tell you (if you're in the middle of significant endurance event) is that you need to raise your blood sugar. It'd be no more actionable than a writing 'your blood sugar is low' on your hand with a sharpie.