Blight + Wither (question about hinder)

Hi, have some questions regarding Blight and Wither mechanics.

Gem setup:
Blight + cast when channeling + Wither + faster casting:

1. If I use Spreading Rot Jewel, does It apply it's damage boost? How to know which source of hinder is effecting the enemy?

2. Can I get both Wither and Blight stacks to affect enemies for increased chaos damage on them? 20 + 20 stacks.

3. Is there a better way to increase chaos damage output without using totems for debuffing?

EDIT: Nevermind, they are both channeling skills and CWC doesn't work between them.

But what if I let a totem cast wither and I use blight, will the damage boost from jewel apply?

"

homdonau wrote:

But what if I let a totem cast wither and I use blight, will the damage boost from jewel apply?

Yes