I think yes, from what I’ve seen xcb is going to be required, or at least for now that’s a reasonable workaround.
Regarding Singularity, I haven’t done that myself, but Docker works with Slicer (at least older Slicers) and perhaps Singularity would too. I ask, since you indicated Singularity is available to you for the trako project, but I don’t know if it will work for this too.