They are indeed saver awards fare code X. I have, however, understood Star Alliance partner award inventory to generally be open equally to Star Alliance members, so if a SQ award is bookable through UA/MP it should also be bookable through SK/EB, hence why many use UAs superior awards finder as their go-to method of finding Star Alliance award availability. It is my first time dabbling in this, so please correct me if I am wrong.

I have stumbled upon this post which indicates there may be substantial problems when trying to book SQ awards through SK but that was a year and a half ago, so I hope it has been fixed.