A lot of ele shamans have been pushing higher numbers by heroing at 1 sec and swapping the legendary from uncertain reminder to another legendary and still benefiting from the +75% duration hero
This isnt an exploit, its just “how to optimize your pull” the effect of the legendary item looks a bit useless without using it like this, its just giving an interest to the item.
In the same way, as DH you can macro a switching build between full mastery and your normal gear to pre-pull your chaos blades with a better dmg bonus.
Its just a way to see wich one have a good gameplay and the others
There is no way that it is intended use for a legendary to be changed during the pull timer and its highly likely that this will be changed.
Parses using this trick should be flagged as at risk
“A rank with a dark gold background is considered “at risk”, since it is using tricks that will likely be hotfixed at some point in the future. If an in-game hotfix is released, then the rank will be removed.”
It is one of the best legionaries
https://www.stormearthandlava.com/elemental-legendary-guide/