I don’t expect the duplication to be too much more of an issue here than Reddit. The only big difference is that duplicate forums can have the same name here. I mean, how many meme subreddits were there? At least for me on beehaw, when I search for communities it shows how many subscribers there are. In this period of rapid growth, it’s certainly a bit of a crapshoot and you may need to regularly search communities to see if any take off, but I expect in the next month or so, some communities will become large and their duplicates will pretty clearly die, just like with Reddit.