When the mysa heatpump thermostat is added to HA, fan controls are not linked to the climate entites. Two entites (fan.xx and climate.xx) are created in one device instead instead of being combined in one entity (climate.xx).
I thought it might be mysa’s fault for not exposing them properly, but below we can see that when added directly to HomeKit both entites are linked in the same entity.
(Mysa Smart Thermostat for ACs (review) - Homekit News and Reviews)
To compare with the integration of Sensibo the fan and climate controls are linked in a single entity.
I only realized that this was possible with the new card features of core-2024.1 because the mysa fan control didn’t appear in the card.