I went to the parade Sunday, skipped Monday (my nephew was disappointed with the beads from Sun so elected to go ride Gringots instead), road the Earth float on Tuesday, then went to the parade again on Wednesday.
Sunday, stood in front of Minion Blast and hardly got any beads. Did the Dine and Ride on Tuesday and we ran out of beads right about that spot. By the time we made the turn by Today Cafe, pretty much our entire float was out. Wednesday watched the parade across from Transformers and cleaned house on the beads.
If you go wanting beads, get pretty close to the beginning of the parade and remember that it runs in the reverse of previous years.