Another observation from this week's theater viewing:
Makeup effects. So one play had a villain with a scarred face, and ultimately the actor gestured to it and the dialogue explicitly noted the character's "bad face" such that it became clear that the character's deformity was, in fact, manufactured as part of the production. But initially no mention was made of it, and with the dim theater lights and my distance from the stage (and perhaps whatever visual impairment I retain from my retinal detachment issues) the makeup seemed convincing enough that I thought the actor might actually have been injured in a fire.
So until the artificial nature of the scarring became apparent, I was decidedly uncomfortable -- because I wanted to watch the play, but I also didn't want to rudely stare at this actor's deformity (even though an actor with an actual deformity would have to have made peace with that scenario). So I think if I felt a need to have a character present as such in a production I were directing, I'd probably want the effect sufficiently unrealistic in order to immediately key the audience in on the deliberate nature of the character's appearance and thereby relieve the audience of any undue discomfort.
(Now I'm wondering how the makeup sitch will play out with Waffles in Uncle Vanya.)