In 0.38 you included the switching function for fritz! DECT 200. Maybe you now could integrate the heating device fritz! DECT 300. Its not much more effort needed. I would love to hear that this Feature will be integrated.
Cheers,
Pascal
Anyone? 
The Problem is the underlying library, which is not compatible with the dect 300.
Would also like to see Support for the Fritz DECT 300 Thermostats 
Me too but like I said earlier the library has to be compatible with them first.
Seems the libary which ist used for connecting to the DECT 200 Switch Devices will never support the DECT 300 Thermostat Devices.
Maybe support can be added with the TR-064 protocol https://bitbucket.org/kbr/fritzconnection which ist also used in FHEM and OpenHAB for connecting to the Fritz DECT 300 Thermostats (I think so…)?
But I have noch clue about developing, so don’t count my words 
take look on this post: