There seems to be a JSR223 script implementation, mentioned in Jsr223: script collection
I didn’t try that out myself, but looking at the code shows, that it should do it’s job, especially if you extend it by some additional data points, which should be easy with a script.
I personally use FHEM with 79_DBKM module to read the data from my Buderus web gateway and then send it using MQTT_BRIDGE to mosquitto, which I read/write with the openHAB MQTT binding. This allows to read all values from the KM100 and also to write data into it (for example switching between time programs A and B). I could write a tutorial how to integrate these with each other, if there is a demand.
Greetings
Roland