Outside of this forum, in my limited IRL dataset, I’ve found FIRE peops to be quite eccentric and more a loner personality than into board games. But ja, limited dataset 
From this (not quite up to date any more) poll, there are 11 people in BS and BL. That is probably a bit of a low number to get 4-5 serious contenders from…
the results
Best to ask around at a meetup as those are the people who actually have time IRL, I think.
And when you say board games, could you give a few examples? I suppose the most FIRE’y game would be Monopoly, right? 