I think 3 or 4 could be too many – but that’s just my option. 2 would be ideal.
If you had lots of options for blend modes or mix modes that would be amazing!
Addictive
Subtract
Difference
Colour burn
etc
etc
But also just a basic A <> B
Have you seen this also? Would be a nice integration?
Keep in sync with DJ, Ableton Live tacks, etc?