Unfortunately, unless you've played Final Fantasy XI to some degree, very few players will be able to tell that Lucid Dreaming has a MP regeneration. Refresh was a spell in Final Fantasy XI which allowed the target to restore MP outside of their normal MP regeneration cycle and the XIV development team decided to reuse this term here. Lucid Dreaming says "Refresh Potency: 80" on it so those familiar with how FFXI work would instantly ping to that, but unfortunately the vast majority of players won't have that experience ^^; There are quite a few complaints about that so don't feel bad that you missed it as most people did miss it themselves.

I would recommend keeping Lucid Dreaming up on all your healer's role actions and keep Swiftcast as well. Swiftcast and Lucid Dreaming are considered the mandatory selections for the role selections.

Happy healing