Was there a reason you didn’t stick with having a single sfz and keyswitch for xfade or not?
In the Factory soundfonts library - Software - Zynthian Discourse thread there seemed to be agreement that we prefer fewer SFZ file alternatives for a given soundfont, so that’s how I made it.
If the coding just got too crazy, LMK and I’ll take a look and see if I can make it work.
One nice thing about a keyswitch is that you can configure settings and very quickly/easily compare with and without crossfades. Just hit a key!