The leaf version of MBBS is not a problem. The MBBS strain that attacks the fruit is a problem.
You can differentiate MBBS from anthracnose by looking for cracks / fissures (sometimes in a star pattern) in the black spots, which generally indicates MBBS. Might need a magnifying glass this early in the season. I've already been seeing MBBS this year on Venus and Lemon Zest. Fortunately, the trees have already aborted the majority of the infected fruits and we have a second bloom coming on.