Midi mapping question - Numark NS6ii

Hi everyone. I've been using Traktor for 15 years and was gifted an NS6ii some time ago, and it has been collecting dust in a corner, as I'm not fond of Serato and don't intend to switch over. I recently pulled it out and started creating a map of all the basic features (cue, play, volume faders, etc.).

I wanted to move on to the more complex aspects involving Midi Out. After a lot of work and trial-and-error, I mapped the volume of Decks A and B to the appropriate VU meter. More specifically, with "Learn" enabled, I saw that everything concerning Deck A was on channel 01 and everything concerning Deck B was on channel 2, so after some trial and error I found that the respective channel VU meter addresses are ch01.cc.031 and ch02.cc.031 respectively, and I've mapped them correctly and they work perfectly after some tweaking. However, when trying to map the Master Volume L+R to the controller's master volume VU meter, I have no idea what channel/controller/note is the correct one. When checking the drop-down list of midi out options, there are 16 channels, each has 127 controllers and dozens of notes that can be assigned to a function. Meaning there are thousands of needles in the haystack when searching for the right one!

My question is as follows: is there any way, any software, I could use to find each function (passive like LEDs, not active like buttons) of the midi controller in question beforehand so that I can know what to map to it, instead of having to brute force it and trial-and-error each individual possible permutation of out thousands, given the hundreds of options for each of the 16 channels? For example (as dumb and science-fiction-y as it may sound), something that triggers each possible midi channel for half a second so that it lights up and shows me what the right midi address is?

I've used MidiView and MidiOX but these only track inputs, i.e. buttons/faders I can push/move, not passive stuff I can't interact with like LEDs and VU meters. Even with Midi Out tracking enabled and using Serato for which the NS6ii has been programmed, I didn't see anything change when I had a track play and increased its gain to see the Master Volume VU meter also start increasing.

Short version: the NS6ii has a Master Volume VU meter. Is there a way to easily find its midi address (channel/controller/note) so that I can map Traktor's Master Volume L+R to it?