Try realtime

[DoganM95]

Try changing and showing the currently set brightness in realtime.
Setting a virtual pin takes time and blocks (sync).

-> try changing every component in its own thread (async)

[DoganM95]

Another approach:

Give each widget a separate thread to poll the current state from.
This way, setting one lights state globally would update every widget on change every x milliseconds (polling cycle time). Would remove lags when moving the main slider in realtime.