Started to tinker with the rules and setting up a relay system. I think I'm making progress, but have hit the "end of my day" already, so it's off to shower and sleep for me. One snag though. When I use the physical buttons, tasmota recieves a "tuyareceived data" thing that basically has the serial data for each fan speed. I put that into a rule and had it do a "power2 on" rather than an MQTT publish. This synced up the relays on the web gui with the physical switch status, and your suggested rule allowed web gui changes to go the physical switch just fine. However, when the fan is turned off, the "speed relay" associated also turns off. When the fan is turned back on, the physical switch remembers the speed it was on last, but Tasmota doesn't, and apparently doesn't receive a "tuyareceived" status to update it.
I haven't began the "link to hubitat" process yet, so forgive me if this would be alleviated during that, but would that "missing speed data" create an issue on Hubitat's side of things?
I'll continue to tinker and either come back with issues, or return with a grand success story that I'm sure somebody somewhere will be happy to find via the google machine. Thanks for your advice and suggestions thus far. I'll keep you posted!