Not sure if this has already been addressed on the PTS, but on live it's possible to bring the Aylied Well buff from Gold Coast into Cyrodiil and enjoy the max HP increase. The well only increased my HP from 44K to 47K in PvE land, but in Cyrodiil I went from 44K to 51K HP. Apparently giving much more than 10% HP by any logical metric.
Now, it lasts 10 minutes. But that is still significant, considering emperor exists, and the fact that you can simply leave out of Cyro and go back in with the buff and have many different skills far more powerful thant hey should be. I also never checked if it stacks with Cyrodill's Aylied Well.
Anyway, is this intended or not? Most of the other HP increases from PvE do not work in Cyrodiil, so why is this one the exception? Does not seem intended to me, and it is obviously open to being abused on live.