Aiwendil- I was mostly just clarifying what the issue is. That it's not the length of the spell but the length of the visibility. I think the spell being longer is a good thing. I just thing the current effect being longer isn't so good, and I don't like deleting them because I like to know what people are casting.
Eonwind - I would agree that they should be visible, because it's a nice guide to let you know when something ends. But most don't stay visible. Defensive wind and attack boosters like flaming weapon are the ones that do, but then the effect is either focused on your hands or low down on the ground, so those are either not too big or not too centralized on the screen. Flame spire is big and covers your entire character, so very centralized and (I find) massively distracting. You also can't really see through it, so it can interfere with visibility a bit as well. If it could be reduced in intensity it would probably be fine though.