Although we have not actually tested this, it should be possible for applications to make Fanout speak the MQTT over WebSockets protocol (and if this is not pos

Although we have not actually tested this, it should be possible for applications to make Fanout speak the MQTT over WebSockets protocol (and if this is not possible then I'd consider it a bug). So it's not that the two are incompatible options necessarily, but that you could use Fanout to scale out such an implementation.