It becomes more annoying and actually less specific, the more I fiddle with it.

I basically need to make a shader that is blurry refracting/glass but clear when viewed head on, so I use Layer Weight and color ramp to tune it in:

The problem becomes worse when I change the color ramp slightly:

Also, this happens when you make glass IOR 1 with some roughness and mix it with transparent and render with GPU:

it is almost black but should be 80% transparent

BUT, when I switch to CPU, then:

It's fine, thought I just mention it, maybe related somehow, turning it on CPU doesn't resolve the main problem though.

Also, it would seem that it is somewhat dependent on the glass shaders roughness.

With roughness 0.2 it is somewhat usable at certain other settings:

But with 0.4

And 0.6