I finally got it to see the other thermostat and its features by renaming all of them (have to wait for 1 minute so HS commits the changes). Even after changing it back to the original name EasyTrigger can still see it. So somehow the renaming did something so EasyTrigger can see it. HS actions could see the thermostat and it's features just fine. Of course, in HS4 you first have to select the thermostat and then the feature but again, it saw all of that without having to rename the device and the features.
No cooling setpoint before renaming:
Cooling setpoint after renaming:
Cooling setpoint after renaming back to original name: