You can edit your XTCproject as if it is a scope project with no Scope mixer and that you can't see routingwindow but with all the various possible routings you need.
Add multiple channels to asio dest/source modules (you may also ignore the merge module and directplaymixercontainer, or not), and multiple wave dest/source if you need and link directly.
There are Mix M/S modules and Switch It, in the devices area, capital for mixing multi INs to one Out inside the XTCproject.
It's possible to interconnect the sequencer and/or every other audio application.
Just as a simple example, I send a wave source1 (DVDplayer) to an asio dest (audio CH with Vst/XtcFx) this goes to asio out--->to wave dest (wavelab recording) this goes to wave source2--->to scope out. (this can save resources for those with few DSPs and no powerfull graphics)
It's also possible to record several vsti and/or audio channels in one go (not only as a final mixdown).
Route the asio outs you need direct to asio ins
---Never do this with main asio out (sequencer main out BUS) and keep sure that the audio channels where you're recording (and those you don't want to rec) ALL must be sent to main out BUS---.
Good routing is important when using GSIF source too and it works fine in XTC.
It's also possible to create different XTCprojects, saving each one as XTCproject.pro to an individual folder (maybe with a kind of task suggesting name) and moving the desired file to the SFP/App/XtcApp folder before opening the sequencer. (maybe not much needed but easy)
I'd share my projects but I don't know how to make a screenshot

though I hope this will be helpfull for someone.
Cheers, Ze.