I think it is possible for multiple App to trap the same Android Audio Event when earphone is plug or unplug, or certain buttom function, highlighted by
@Electrocrytic . I guess it is up to the OS to maintain state, and also the possible status of DAC device when multiple App accessing the same device. Hence
@Imbrie mentioned it seems to work for him on RS6 but not R6iii at the moment. I tend to expect things to be a bit buggy at first since this is probably Hiby 1st implementation of Android 12, and probably some fair bit of changes from RS6 Android 9 to R6iii Android 12.