pharohoknaughty
I posed a similar question a few days ago but I suppose it was worded poorly, nobody responded.
Its not just Melodyne, but also Vvocal.
Sorry about that, my ADHD kicks in if a post scrolls to page 2 :( I missed it on you.
I just looked in the X3 reference guide quick and did not find a shortcut for Melodyne (to open it if the Region FX is already created). There is, however, one for V-Vocal (go figure)
V-Vocal Shortcut keys: (page 1587)
Command Shortcut
Open V-Vocal Editor SHIFT+V
Create V-Vocal Region FX clip SHIFT+V
Melodyne:
CTRL-M (to create clip from selected area) (Page 1050)
Melodyne may have the same functionality for opening (not tested either), but since creating and opening are the same shortcut for open/create, watch if something is selected that you don't want to work with. I personally think the "double click" the FX header is safer.