Fellow SMNs, why can't we use our shield when we want to?

[Reclusegamer]

I'm surprised no one is complaining about this and yet we have a thread begging for our heal to be functional, even though that even if Square did make the heal functional it's only use will be to take less pressure off of a healer when they have to top someone off immediately after we rez them.

What I want them to fix is Radiant Aegis shield so we can weave it whenever we want like a real oGCD skill, just like Black Mage's Manaward. A +20% hp bubble is great mitigation and I really want to use it, especially since SE gave us a second charge to use. Here's the problems we have with this skill:

1. it takes a moment after you fire it off for it take effect.(Albeit it's a minor issue, maybe intentional. just something of note.)
2. You can only cast this spell when Carbuncle is on the field. If Carbuncle transformed into Bahamut/Phoenix/Ifrit/Titan/Garuda you CAN NOT cast this skill until whatever transformation phase Carbuncle is in ends.

For Bahamut, it's a whole 15 seconds
For Phoenix, I think it's about 10 seconds
For the 3 main summons, their attacks take like a whole 5 seconds to fire off(might be a little longer)

Those are HUGE time windows in which we can't use this skill. Unless you know the whole fight and the bosses attacks in their sequence prematurely beforehand for the whole fight you would have no reliable way of planning ahead of time when and where you would be able to use this ability. Currently I find myself only being able to use this when I see something coming I can't avoid and I just so happen to be firing my charges while carbuncle is out.

Do I just suck or do you believe this should be looked at?