@Jungle_Brothah
If you want to check the VU meters on an individual channel, just hit the CUE button on that channel. This will both allow you to cue the channel in headphones and will switch the VU meter to display the CUE audio level. So here adjustments to the master volume will have no effect on the VU meter display.
If you deactivate the CUE on all of the channels, then the VU meter will display the master audio level.
So instead of having a cue/master switch on the VU meter, this is done for you automatically when you select and deselect the cueing functions.
Hope this answers your question