As mentioned in IRC some formats do not work in Calamares. It would be good to compile a list so that we can A:) Document it. B:) Exclude those from the drop-down list or C:) fix the issue. Further, for the file systems that do not work it would be good to test with another distribution to see if the issue(s) is(are) isolated to (L)Ubuntu.
@svinoba would you be willing to put together a list of what doesn't work?