I'm a super duper secret service agent with top level clearance at the NSA.

Honestly, it took longer typing out this comment than it did to find and (semi?)-confirm what I suspect.

But seriously, all that was needed was a little googlage. Googling his username bought up the YouTube channel, but a YouTube channel by itself isn't conclusive, so I took /u/JoeDart (his suspected alt) and did an advanced search for him and his suspected alt which gave a Disqus profile name choppy sean.

In this profile I noticed this little gem where a user called "Joe Dart" seems to criticize "mineimator" and its pricing, which appears to be a bit of animation software, or a service to make Minecraft animations. A user posts by the name of Choppy Sean, where he states...

Joe Dart is right, Cinema4D has all these features you can't get out of mine imator atm, The site is simply if you want an amazing animation, besides, when you buy from my site you can state the entire storyboard... It's custom

So, you have Joe Dart criticize a product, and Choppy Sean pop up out of nowhere to offer his fantastic, better alternative. It seems a little strange that Joe Dart pops up to back Choppy Sean up on Reddit, and also happens to hang around the same posts as Seany boy on Disqus, where he offers up a comment that conveniently allows Seanerino to segue into offering a service to sell? Perhaps he's not an alt, but a good buddy that he can ask to back him up when the time arises. Though, Joe Dart has been called out on Disqus too, for being an alt, so there's that lol.

Anyway, to make sure I wan't blowing steam out my ass making a comment I couldn't at least back up, I figured he is an animator, his Disqus profile has a YouTube video of his work, so he has a presence on YouTube, so I just searched "youtube, choppy sean, and animation" and it results in the same channel I suspect is his.