The most important thing on the debate stage (I believe it was the same stage for both the presidential and vice-presidential debates) is not visible due to the camera angles in most of the photographs, but is visible in eg this photo: about 12ft directly above each candidate’s head is an air vent pointed down, connected to a long air tube leading offstage (presumably outside or to some other known-good air source). Those are presumably positive pressure, to prevent the candidates from breathing any air from the audience. So assuming the flow-rate was decent, I think modeling the debate as “indoor” for purposes of candidate-to-candidate transmission is probably a mistake; both candidates were likely well-protected from each others’ air. (The audience and the moderator, on the other hand, would have been at risk from Trump, unless there are additional vents I haven’t spotted.)
The most important thing on the debate stage (I believe it was the same stage for both the presidential and vice-presidential debates) is not visible due to the camera angles in most of the photographs, but is visible in eg this photo: about 12ft directly above each candidate’s head is an air vent pointed down, connected to a long air tube leading offstage (presumably outside or to some other known-good air source). Those are presumably positive pressure, to prevent the candidates from breathing any air from the audience. So assuming the flow-rate was decent, I think modeling the debate as “indoor” for purposes of candidate-to-candidate transmission is probably a mistake; both candidates were likely well-protected from each others’ air. (The audience and the moderator, on the other hand, would have been at risk from Trump, unless there are additional vents I haven’t spotted.)