v176 Toon Forest Vignette problem

Petercat

Is anyone having problems with v176 Toon Forest Vignette taking way too long to render?
I have a 980ti, and 64G system RAM, it was kicking over to GPU/40+gigs RAM.
I turned in a trouble ticket, but got too close to the 30-day refund limit, and had to return it.
Now I'll never know what the problem was, or how to fix it if it occurs again.

I can render an 8-figure indoor scene with emissive lighting in 30 minutes, 2000 iterations.
Toon Forest by itself with two emissives took 30 minutes for one iteration, if it didn't lock Studio.
Can't test it anymore, as I've deleted it.