This is not exactly a new idea, since an old version of Logos (and perhaps Logos 4 in the current version) allowed to full justify the note text pressing Ctrl+j.
Another undocumented feature is currently working on Logos 5: you can still select the text in a note, press Ctrl + j and see the text justified when exporting it as a Word document and others formatted docs. Unjustified texts looks messy, so please implement (again) this feature in future versions!