Setting the brightness in the control-device node

I’m using the node control-device in node-red-contrib-ewelink-cube and would like to set the brightness of a lamp. Any suggestions on how to pass the msg.payload value to the control-device node?

Would also be interested in this. Multichannel devices also have multiple actions in the control-device-node but I would like to control only a single channel at once.

Another interesting questions for the custom registered device how can I alter their state with a previous message payload / variable. i.e. below to change “on” with msg.payload