KNX using free group address system

OK, good to find this Information after almost one day of debugging my configuration.
KNX 1 Binding had support for this format. How can a user find out about a missing support in the successor version? Even a Trace of “calimero” and “org.openhab.binding.knx” does not give any indication on a missing support for 1 tier addressing. I just got:

20:43:01.741 [DEBUG] [x.internal.handler.DeviceThingHandler] - None of the configured GAs on channel 'knx:device:bridge:generic:Light' could handle the command 'ON' of type 'OnOffType'

Please add some warnings into the documentation or just add support for this stuff.
Now I know the Issue, but for others it might be as frustrating as it was for me.

Thanks a lot,
DcDoM