Equal exposure time for filters aims for the paper's ISO speed point, which is at 0.6 plus b+f density. This is lighter than Zone V, which has a density of 0.75, but the whole idea of not changing the exposure time when changing contrast only works with calibrated enlarger setups anyway. And even then, it's safe to assume that exposure needs to be slightly adjusted after a contrast change.
For most prints, I teststrip the exposure for the highlights and adjust the shadows with contrast. If you get significant highlights and shadows on one test strip, you can determine exposure and contrast in one go.