Apparently my versions of The Isle and PixARK are so ancient that they are no longer supported. No idea when I got them, but that likely explains my issues with them. Probably got them as part of an alpha test or free playtest period or something else. We will definitely pick these 2 up at some point to check out.
Super Mega Baseball 3 is the closest thing to a baseball MMO that I'm aware of and despite it suffering from some strange controls (at least from the perspective of a huge fan of MVP Baseball 2005 and titles of the 90s and 00s) and input lag. It's full-featured, though. Definitely a high quality title for baseball fans. Recommended!
Angeldust is a work of art that I can tell a lot of time went into crafting it. The problem is that most MMO players will find that there isn't anything to do after building your base. It's definitely a niche product and I wish the developer the best! Borderline.