I've certainly gotten into the habit of "interviewing the interviewer", in a reasonable sense. After all I'm looking to see if the job suits me just as much as the employer wants to make sure I suit the job.

But I've never considered asking a full interview worth of questions over multiple sessions. "As much as, if not more than" seems really exaggerated. That implies that candidates are asking 30-60 minutes of questions straight, then doing it again a week or two later. Maybe even asking the employer to do a take-home? I can't imagine the look on an interviewers face if I asked them to do a take-home.