Eurotronic Spirit is supported out of the box in HA.
“current temp” from an external sensor was not supported in a proper way as I remember from a year ago. I could not set it in HA because my external sensors are Xiaomi sensors. When another ZWave temperature sensor is present, it can be somehow be set as external sensor for Spirit, but I think for that you needed Domoticz or something…
For the time being, in HA Spirit has it’s own ‘temperature sensor’ and ‘offset config’. By utilizing those two, you can use an automation to manage offset from external sensor, so that internal sensor shows the same temp as external one. Here is the code: Eurotronic Spirit Z-Wave - external temperature sensor
Limitation is the offset value, it’s ranging from -5C to +5C with 0.1C step.
Some more reading on external sensor issue here: https://github.com/dresden-elektronik/deconz-rest-plugin/issues/1098
What nice feature it has - direct valve control, if you make changes to discovery_schemas.py from here: https://github.com/home-assistant/home-assistant/issues/14526