Knx rgbw brightness slider missing?

Hi! I have an MDT KNX LED RGBW actor. If I configure it via RGBW group addresses, I am lacking a brightness slider in the visu.
Config:

knx:
  light:
  - name: "EG-LED-ALL"
    address: "0/3/11"
    state_address: "0/3/12"
    rgbw_address: "0/3/13"
    rgbw_state_address: "0/3/14"

I get it visualized like this:

If I add brightness address, I get a brightness slider and all is fine. But that creates additional effort in configuration.
Also, why do I have to configure the address to switch it on and off? the actuator can be completely controlled just via RGBW group address (it turns on/off automatically depending on RGBW values).

I am new to HA, is it me wrong thinking, bug, feature or feature request?

Thx
Daniel

The switch address is used to turn it on and off. If it was done via rgbw address a turn-on color would have to be defined in HA. With using the switch address the configuration of the actuator is respected properly.

For the brightness address I have no idea, I don’t run rgb lights myself so I never tried this.
You could eg., with according actuator configuration, send brightness values throughout the day without turning the light on. So whenever the light is turned on the brightness is set for the current daytime.

Keep in mind that this should work with all KNX actuators not just one specific manufacturer/configuration.