Chord naming is one of my priority items. That Finale does not include the minus symbol as a default for a minor chord, for example, is insane and one of the many issues I intend to address during the next beta round.
Such flexibility has never been possible in Encore and it would be a wholly new feature so I’m not expecting it in the first release of 6. I’d like to see it added, though. For those of us who do lead sheets and small band projects, custom chord symbols that could be saved would be a timesaver.