Sorry but the best I can do is uninformed!
Simply the crossover cards are either 12db or 18db on the 5234 so I am not sure what the crossover does?? Does it maintain the proper phase relation ships between high and low pass or invert like you would a passive crossover so you would have the same phase relationship between drivers as the passive crossover??
I use a 24dB L/R set-up to. I have my drivers in phase. I know the crossover does not invert phase from high to low pass. It has the option to do so if required. My crossover does not have a delay option so I can't fine tune or compensate for driver distances IE horn loading of the bass or compression driver. Theoretically without path differences you would be one cycle out of phase at the crossover point.
I am a babe in the woods with active crossovers very much on the learning curve, hope I am correct hope this helps
Rob