This won’t work as the fans it doesn’t take into account the fans being off. I would have to add a FAN=off so it will start. Also, what happens when there’s a change in the temp? So with
TEMP >=74 AND DIM<30 OR FAN=OFF
the fan will start as the temp and off conditions are true. When the temp changes, won’t the rule reevaluate itself and shut the fan off since it’s now neither the <30 or =OFF are true?
Result: It sent the fan into an on/off loop.