FluxBB upstream support and maintenance is doubtful at this point and probably going to decrease only from this point forward. We considered many alternatives but basically, it turns out that there's only really NodeBB and Discourse. Just to be clear: We're also unhappy about that fact but it doesn't seem like many people are developing modern forums anymore. However, we're also unhappy with the security implications of an unmaintained FluxBB. Additionally, it doesn't seem to do SAML or OpenID Connect-based auth either, so we'd have to hack that in.