I am using the Abyssal Echoes skill with Void Purifier and Vorpal Explosion nodes.
Void Purifier states
Abyssal Echoes’ initial burst now also heals you and your allies and nodes on this tree that grant more damage also grant more healing.
and Vorpal Explosion deals 80% more damage.
I am expecting the heal from Abyssal Echoes to be 80% more. In my testing however it does not seem to work. However, healing effectiveness does (I have 16%).
I am using Titan Heart to stop healing per second and see my health before and after Abyssal Echoes heals me. I start at 782 health and after it heals I only have 840 which is a healing value of 58. This aligns with 50 * 1.16 for my healing effectiveness.
Screenshots of my Abyssal Echoes tree, character sheet, before and after healing can be found at https://imgur.com/a/cEWDKIB