Nutrition plan for long event - fat oxidation rate?

Personally at 8-12 hours/week, my target is 6g/kg of lean body mass (which I estimate at 75kg) or 450g of carbs per day.

Based on a number of sources, randomly pulling up this one first:

And this one:

https://www.gssiweb.org/docs/default-source/sse-docs/sse_231_005.pdf

has some good pics like this:

and a few others.