I'd like to see Finale support simplified chord extension notation.
Instead of G7b5b9, just Db/G7
Instead of G13b9, E/G7   etc
Instead of Cmaj7#11, D/C∆7

..wherein the first member of the polychord contains the extension set.
As an arranger, I've come to think of chord extensions as polychords, with one chord consisting of the primary colors of the extensions... it's readily understandable to advanced players, and greatly simplifies the creation of chord symbols.

Currently, when I try to create a chord like this, Finale erases the extension on the symbol after the /. This prevents the definition of the primary quality of the chord, which should reside in the second of the pair.
The alternative would be to create these as expressions, with the major drawback being they're not transposable.