Hi,
I can shed some light on your 1st setup as its very similar to mine.
First thing I’d like you to know, using the Z1 only for decks A & B, you won’t have an output for the remix decks. IF you use decks A & B for your standard tracks and C & D as remix decks (like I do) then you need to assign 2 channels for C & D. I have an Audio 2, but I mostly use the clubs DJM 800 as my soundcard. When I’m doing this, I get 4 channels for decks A, B, C & D and each of them are routed individually like a 4-Deck setup.
There are times when clubs don’t have USB capable mixers, on those events I use my Audio 2 which has 2 stereo outputs. During these events, my decks are routed as A & C to channel A and B & D to channel B. To maintain parity, I load the same remix deck on both C & D. So when I want to a live remix/mashup of say a track thats currently playing on Deck A, then I’ll use the remix deck D to trigger all the one-shots and loops and for deck B it would be remix deck C.
The drawback of the Audio 2 setup is that I can’t monitor the samples when Decks A & B, both are playing. This only happens when I’m in the mix between 2 tracks. I mostly only use the F1 to overlay loops and one-shots over a single track, so for me, it doesn’t prove to be much of a problem.
Hope this helps!