So lets take the lock out of the equation. And just use presence and the ecobee. When certain people come home, do this with the ecobee, and when everyone leaves (or maybe just specific people) do this with the ecobee.
If you’re familiar with custom device handlers/apps, I think you’ll find this can do exactly what you want.
I also have an ecobee, and find this to be able to do exactly what you want. Basically it was a simple settings in the app to select ecobee mode based on SHM or Smartthings mode. It’s quite customizable.