Economic Profit - when to use BV and when to use MV

In equity we show this formula taking WACC from book values.

In corp fin it does not state explicitly. Is it the same or market values?

WACC should always be market values, shouldn’t it?

In Residual Income EVA (which is basically economic profit) uses book values. I guess this is just specific to RI which assumes all its models on BVT-1 ?