Interaction of Sunder and new Shockwave support gem

So this following question is either a stupid or genius one:

Sunder states "shockwaves deal 60% less damage" which refers to the shockwaves the skill releases when it hits enemies. Now if I link the new support gem "Shockwave support" to sunder, how exactly do these two skills interact with each other?
Will the new shockwave support gem simple proc on the first enemy that is hit by sunder? Will it do 60% less damage or be unaffected by that reduction?