What to do with the crossfader?

What to do with the crossfader?

I have had a xone2d for a week now, and I am having a great time with it.
I’ve been working on a 2 deck internal mapping, and have it pretty much finished.
The only problem I have is, what do I map the crossfader to?
I use the volume faders, eq, and filters to mix, and never use a crossfader.

I mainly play minimal and tech house with a sprinkling of techno/house.

Any ideas what to map to this xfader? I already have deck focus buttons
so a single knob effect would work.

Or a good transition effect? I already have armyofme’s build up mapped, so that one’s out.

Loop size selector, seek position, another sweep?

Already have loop size and seek. Any suggestions for another sweep? I might try to work one out tonight too.

Keep peak filter and reverb then try experimenting with other effects flanger-flux, LOFI, delay etc. I also like T3 reverb in advanced mode combined with little amount of LOFI and drive to create a build and then bring gater or masher and before the drop engage transpose or TTFX.