CPFF - billing labor category not originally in proposal

Hello!

Contractor here, with a CPFF contract for a research effort. Our original cost proposal included a slew of labor categories for (I believe) cost analysis purposes. Our final contract doesn't specify anything about LOE, or approved labor categories. We have a new individual working on this effort (COTR is aware), but he would fall into a different labor category than what was on the original proposal. From my perspective, the labor category name is a moot point as we aren't locked into any specific approved rates via a labor category.

Do we need to provide any sort of notification, or new proposal activity? As it is a cost type, and not T&M I can't find a requirement in writing anywhere. If this does require some sort of approval, what guidance specifies that?

Thank you.