Does the buff we receive from the proc automatically benefits current dots on the target or you need to recast them within the 8s buff duration to gain the 20%?
Buff lasts 8 seconds, and I'm pretty sure you need to re-apply your dots, they said they fixed the registering of damage on various procs but it isn't the case.
Dots don't get updated when you get a buff. Recasting your dots is most of the time a dps loss, only exception is bane of doom, but with proper use of cooldowns you normally will have a BoD on your target that is stronger already meaning you wont have to recast it.