(Even in the play it's based on, it's clear the author didn't really understand the Revolution.)

I've read a few excerpts from it (the ones I could get for free online) and some of the characterization is definitely strange, probably the result of the author's obsessive fixation with Robespierre that, to my understanding, is somewhat irrelevant to the real Robespierre. I read enough to realize I should not be reading this until I finish my current project researching the trial of the indulgents lest it influence my conclusions in strange ways...

It has nothing to do with the Revolution as portrayed in reputable historical sources...but people think it does. If people realized that everyone and everything in it is not merely a caricature but a caricature of a caricature, then perhaps I wouldn't have such a problem.
That seems to be the problem pretty much all historical fiction (and even some historical fact...) about the Revolution, or most of history. People tend to forget about the "fiction" part of "historical fiction" even though it is clearly stated in the title of the genre!