Thanks for the info… I am going to look into this more but what I would do is use the 
Toilet Exhaust Fan with time delay BP. Use the push button as the trigger (may need to do something here but you need an ON state), use normal mode, don’t use the wait time, enter in your fan and set the delay time to 5 min.
What I do it have a Shelly on my light in the toilet so I can see if it is ON or OFF (that is all the Shelly does, we still use manual control) and then I use the light as the trigger, normal mode, use the wait time and set it to 2 min, enter in the fan and time delay of 4 min, Use time from 8am till 10 pm every day. Everyone loves it.
Blacky 