the best i can explain it is, first multishot is factored into status chance (as in, how many procs u get per shot), and then it is factored in again because beam weapons combine all the projectiles into one projectile beam (multishot times base projectile dmg) and this is what all the status procs use for their damage calculations. in other words, we get normal amounts of status procs from multishot and each status proc uses a base dmg value of multishot times projectile dmg, so we double dip on it.