Is there a Climate template integration?

I see that. This is the reason I initially discarded the idea of using Generic Thermostat and only tried it after reading the post from @tom_l here.

In OH3 it’s actually pretty “easy”:

// Modbus
// Alle Items auf autoupdate:false, da es sonst beim Schalten zu häufigen Statuswechseln kommt, siehe https://www.openhab.org/addons/bindings/modbus/
Group e_Sauna_Ofen										"Ofen"								<heating>	(r_Sauna)							["RadiatorControl"]				{ ga="Thermostat" [ roomHint="Sauna", name="Sauna Ofen" ], alexa="Endpoint.Thermostat", homekit="Thermostat"  }
  Number:Temperature	Sauna_Ofen_Temperatur_Aktuell	"Aktuelle Temperatur [%.0f °C]"		<heating>	(e_Sauna_Ofen, u_Persist_Change)	["Measurement", "Temperature"]	{ channel="modbus:data:readonly:currenttemperature:number", ga="thermostatTemperatureAmbient", alexa="TemperatureSensor.temperature", homekit="Thermostat.CurrentTemperature" [minValue=0, maxValue=100] }
  Number:Temperature	Sauna_Ofen_Temperatur_Ziel		"Eingestellte Temperatur [%.0f °C]"	<heating>	(e_Sauna_Ofen, u_Persist_Change)	["Setpoint", "Temperature"]		{ channel="modbus:data:write2:setpointtemperature:number", ga="thermostatTemperatureSetpoint", alexa="ThermostatController.targetSetpoint", homekit="Thermostat.TargetTemperature" [minValue=20, maxValue=100] }
  String				Sauna_Ofen_Modus				"Betriebsmodus"						<heating>	(e_Sauna_Ofen, u_Persist_Restore)	["OpenState"]					{ channel="modbus:data:write1:oven:string", ga="thermostatMode" [ modes="heat" ], alexa="ThermostatController.thermostatMode" [HEAT="heat"], homekit="Thermostat.CurrentHeatingCoolingMode, Thermostat.TargetHeatingCoolingMode" }

This creates a perfect representation of the actual device (on/off/current temp/setpoint temp) for Google Assistant.

Back to Home Assistant:
Your solution leads to the device not being controllable by Google Assistant unfortunately (see “third approach” in my post above). Or can you export an input number as part of a climate control for Google Assistant?

That would be great, can multiple entities in HA be exposed to Google Assistant so that it sees it as “one device”?