Assign Decks and Submix Tracks to Mixer Channels (custom mapping)

Currently the deck to mixer assignment has a fixed mapping.

Deck A -> channel 2
Deck B -> channel 3
Deck C -> channel 1
Deck D -> channel 4

It would be great to be free to do our own mapping or to choose between alternative mappings

Deck A -> channel 1
Deck C -> channel 2
Deck B -> channel 3
Deck D -> channel 4

or

Deck A -> channel 1
Deck A -> channel 2
Deck B -> channel 3
Deck B -> channel 4


Additional to the deck mapping it would be great to be able to assign a submix (stem track, remix deck) to a mixer channel as well.
Multiple submix tracks can be assigned to one mixer channel

Deck A, Stem, Remix Deck track 1 -> channel 1
Deck A, Stem, Remix Deck track 2 -> channel 1
Deck A, Stem, Remix Deck track 3 -> channel 1
Deck A, Stem, Remix Deck track 4 -> channel 2 ( Vox to apply separate FX )
Deck B -> channel 3
Deck D -> channel 4

To assigne a deck to a channel:
press and hold the deck button (if the deck is already selected) + the cue button to select the mixer channel

To assign a submix (stem, remix deck ) to a channel:
press and hold the stem select pad + the cue button to select the mixer channel

Deselection (toggle):
press the same buttons for the deck/submix again.

I would see this a huge improvement over the current behaviour and may attract DJ's to user more often stems and remix decks. I see the current possibilities how you can mix a submix channel very basic if you are not on S5 / S8 / D2

Use case:
I like to load the same track in 2 different decks. With the EQ I separate a certen range to apply an FX to a certain frequency range.

Channel 1:
Low Eq = 50
Mid Eq = 0
High Eq = 50

Channel 2 (same track with FX1 on):

Low Eq = 0
Mid Eq = 50
High Eq = 0

If I want to do now any tempo adjustments or looping the 2 decks will run out of sync :-(
With free deck mapping I would need to load a track only once and would be able to assign it to 2 mixer channels

What a cool feature