I think the problem would be that people'd be biased to vote for Atku cuz of the joke rather than the actual quality of the story. Or they'd at least be influenced by it.
That's possibly another good reason for anonymous submissions.
I'd say the opposite. Aktu's submission wouldn't be that funny because it would be anonymous, missing the point of even creating the new profile.
I'd vote against multiple submissions. It'd be unfair to both slow writers and voters, giving way more weight to whoever could pull 2 or 3 stories in the month and multiplying the amount of things to read to unmanageable amounts.
Multiple submissions, non-anonymous, could be a thing I guess if the theme ever was "flash fiction" allowing the same person to publish one to three 500 words max story, in series or independently. So that the final amount of material would stay manageable.
I honestly believe that multiple submission would lessen the quality of publications, even if anonymous. I mean, some might pull it off, but I myself spent a long time polishing my last story, and trying to fit two in the month certainly would have degraded the final quality.
All of that being my humble opinion.