Smart thermostats as part of energy provider sign up deals

Not sure if this is the right place for this question but I've recently upgraded my boiler and while I was on a single zone beforehand I'm now on a dual zone system. So my Netatmo is no use anymore.

Anyone know is it ok to switch energy provider again and choose a different provider that supplies a dual system smart thermostat as part of the sign up deal? Can you get the thermostats twice? I remember hearing that's it's an EU grant based system and there's only one grant per customer but not sure if I heard that correct. If someone has more information in it it would be appreciated