I tried searching for "cast time", "bug", and "menu" in the topic and didn't notice anything, so at the risk of attracting ire I'm going to point out a (hopefully new) bug.
The "time spent in ring-menus advances the cast timer" vanilla bug seems to be back even though it's mentioned as hopefully-fixed in previous versions of Sin of Mana. I don't know whether other time-freezing effects advance the cast timer yet, I'm still fairly early in the game.
I'm running the 1.200 patch and tested it by casting Fireball with Angela right after learning it on the Golden Road:
Cast fireball on your favorite rabite, bring up the X ring menu, wait about ten seconds, drop the menu. Spell comes out instantly.