If you had 2 P-basses; one for flats and one for rounds, and one with a maple fretboard, one with rosewood (or similar)...
Would you put rounds on the maple board bass to further exaggerate the brightness and flats on the rosewood to further exaggerate the warmth?
Or put the the rounds on the maple board bass to slightly tame the brightness back in and the flats on the maple board bass to "brighten" it up?