There is nothing in the party plan that states a canvass can't be conducted for a majority (rather than plurality) outcome. It is typically not done that way, but it would only require an ordered preference ballot (first choice, second choice, etc.) with lowest first choice getting dropped off after the first round of ballot counting, and so forth. You can also call a pre-canvass to determine who will be on the ballot for the actual canvass (i.e., the top two vote getters). Just because the model call for a canvass doesn't do it this way doesn't mean the Plan prohibits it.