I have my Xone:4D connected to my laptop using Traktor Scratch and a pair of Technics 1200mk2 vinyl decks

Using the soundcard of the 4D in Traktor via USB I can use Traktor effects on anything that is plugged into the 4D.

I have Ableton Live 9 on my other computer, and have a Focusrite Saffire6 USB soundcard connected.

I can have the output of the saffire 6 and run the effects of traktor over it.

however I have tried connecting the Saffire6 to the FX in/out of the 4D so I can also use the effects in Live 9

It does work, but with one problem...
There is a bad delay through the Saffire6. I can add a delay value to the track in ableton so that beats are matched between traktor and ableton, the best I get is it matched but out by a beat.

I'm assuming (not tested) that if it was the 4D soundcard with ableton there would not be a bad delay, however I would loose the timecode functionality with traktor.

In testing the Saffire6 and Ableton in the Fx send loop, I could only get it to work in a way that you get the 4D outputting a dry signal together with the fx signal, rather that just one signal.

Is there a solution or workaround to get this working?

Has anyone got anything working with the fx loop? like a Pioneer rmx-1000, or a Korg Kaoss-Pad for instance?