Tension is key. Araki, (if you don't somehow know writes JoJo) uses the visual language of film to communicate Comedic or Dramatic tension as the dialogue goes on.
A slow zooms, sudden changes in color, breaks in the 180 degree rule, all can keep the audience visually engages enough to consume your info dump or long debate.
Also, minimize the number of shots. Lots of larger panels, with less visual information in the background to help reduce the conflict of noise created by text blurbs.