There are a lot of smartapps that I’ve developed along with my custom ecobee device that could help you in having more ST control over your ecobee thermostat.
(1) One approach is to set the ecobee thermostat to ‘Away’/‘Home’ mode according to the corresponding hello home modes.
The ecobeeChangeMode smartapp may help you in doing so. Refer to
(2) Another approach is to use the following smartapps to change the climate/settings at ecobee based on
some presence sensors.
See AwayFromHome and resumeEcobeeProg smartapps (refer to
(3) Finally, I’ve just recently developed a smartapp that monitors the ecobee’s settings at regular intervals (in minutes) based on an outdoor sensor (temperature, humidity) and some indoor motion sensors to provide more/less heating/cooling at the right time during the day.
You can use all the above smartapps or some of them according to your preferences.
In general, in order to avoid any conflicts between the smart ecobee thermostat and ST, I usually set the ecobee’s holdType input parameter to nextTransition to take advantage as much as possible of the existing ecobee program schedules that I’ve defined.