It looks like the parade starts right by Star Tours. So as long as you watch it right near the beginning and make sure you are on the right side of the street, it looks like you should be ok. MM is just around the corner from there.
I think the official policy is that they give you 15 minutes from your ADR time before they cross you off the list. At least that's what we were told when we arrived at Boma 18 minutes past our ADR time. Luckily, they were able to seat us anyway, but I wouldn't take that chance with MM and the Fantasmic package.
Actually, if I were you, I'd leave the parade at 3:25, whether it was over or not.