Does Swift Cast work on any skills?

[Kaurie]

Just for interest, it works on summoning carbuncles too .
Change them on the run .

Why would you ever change your pet? You pretty much have access to Useful Pet, Useful Pet minus some damage, and Useless Pet as a Summoner, Useful Pet and Useless Pet as a Arcansit, and I'd say two Useful Pets that you'd never want to switch out in the middle of battle as SCH.

Like Rawrz said, my instant cast procs for Fire 3 and Thunder 3 do not consume Swiftcast either, but they also do not consume MP, so is it linked to that maybe?

It sounds that the proc itself makes the spell an ability. That's interesting to know, though.