Quick comment from a French user.
The fractions are mathematical, so will be easily understood by all.
The French notations Ronde (= 1), Blanche (= 1/2), Noire (= 1/4), Croche (= 1/8), then Double/Triple/Quadruple Croche (respectively 1/16, 1/32, 1/64) are commonly used, but they probably won't be so easily understood by people who haven't been trained, or haven't taken the time to train themselves, so the fractions will definitely be convenient, as they make sense to everyone. And you will save space on screen.