Anyone have a node server that works with the Big *** Fans? Or has anyone tested Matter integration with these beasts? 

Do they work with Alexa?  I have some fans that are knock off Big A$$ fans that work with Alexa and I use that as a go-between.  It is actually working quite well.  Using variables Alexa will keep ISY sync'd to the fans regardless of how you control the fans.  I can control them using the fans own remote, Alexa, and ISY and everything stays sync'd.

I have a few Big*** fans, including two Speakeasy models, but I haven't tried controlling them directly via Matter yet. Matter wasn't far enough along on the eisy when I bought the fans to try that route, so I set them up using Home Assistant as my "go between". The HA integration and app easily controls fan speed, direction, and preset mode. I also set up a physical on/off control via an Insteon I3 paddle that signals a Home Assistant automation to turn them on or off.  It works very reliably, and the Speakeasy fans are quite nice.