Poison ABB/SS/Exec/RoS Witch Hunter

So, i decided to respec my DEE WH to this build.

Mainly because i got those legendaries from my other characters and my friends.
Main damage is still Acid/Poison, the playstyle also a bit the same with DEE build.
The cold damage from Execution is converted to acid by using Conduit of Night Whispers,
while the piercing damage from SS/Ros is converted to acid by using Rift Scourge Slicer/Basilisk Mark.
I used to max RoS but i decided to get a one value point.
So far im quite satisfied with it, but i feel like there is something lacking.

Killing Fabius in 20sc

Highest poison tick i have seen (183k)

I only have moderate amount of GD knowledge, so I wish to improve this build further.
Im open for input to help optimize this build, simply point out where i go wrong and what should i do.