
Your only option is to midi map the fx2 and fx3 to buttons u are willing to sacrifice either on your controller or on the keyboard. Like u, I also use vdj and I use Rekordbox from time to time, but even tho the claim is that this controller was "designed" for Rekordbox, it don't make sense of there being no hardware buttons for the fx2 and fx3 when they are in the Rekordbox software.
Even though there are 8 pad effects that can be used, the lack of being able to apply manual value on the fly as it can be done with the fx dials in the RR/RX/RZ per effect and the constant switching of the fx channels between decks is a bit annoying imo. Maybe my interpretation on what's needed on pro gear is a bit off.