Sib professes to be intelligent enough to add chord symbols from notes. Text/ChordSymbols/AddFromNotes. Are ukulele chord symbols different to standard chord symbols?
If you add a Ukelele Notation staff to a score, it should be set up to used chord diagrams based on the tuning of the uke TAB staff associated with the Uke notation staff. To see what that is, go to , Home>Instruments > Edit Instruments, edit your notation staff, and at the lower right corner you will see the tab staff upon which the chord diagrams will be based. You can change to a different TAB staff if you want different tunings.