I have 8 spirits they are setup with Secure RT321 Thermostats per room.
I just picked up 8 Secure/Horstmann/IQE RT321 Thermostats off eBay at approx £20 each
I am using the Heating Scheduler to drive them right now.
Having to use a non Homey zwave Controller to control the Secure SR302 Heating/hot water right now until the bug in the Secure/Horstmann app is fixed :-(. Only thing stopping running everything on Homey.