Hi,
The ST stock ecobee device doesn’t allow a refresh rate below 5 minutes, but My ecobee device can do the refresh every minute if needed.
Also, you can also connect your Humidier/Dehumidifer to ecobee, and then use the MonitorAndSetEcobeeHumidity smartapp which can also turn on/off some smart switch(es) if needed.
The smartapp will calculate the ideal humidity level for your home based on the outdoor/indoor conditions at your home, and then activate the right device (humidifier/dehumidifier/ventilator and/or smart switches) to achieve your target humidity level.
See my github for all the complimentary smartapps available with My Ecobee device:
Regards,