Hi
Please check bellow scene
If I dont have all paths enabled in mantra I see objects under glass black?
I tried mantra glass and my own mantra surface setup as glass
Render is ok with all paths but render times are very long

What is the best strategy for something under glass, water etc.
I dont need caustics so all paths is not necessary for me but it is the only way I see through glass
I had same problem when rendering eyes with cornea over?

I haven't taken a look at the scene but with the Mantra Surface shader you should be able to enable Faux Caustics under the Surface -> Opacity tab.

Yep. You don't need all paths, just enable faux caustics in your glass shader.
Also, Pixar openSubDiv is way slower than the default Mantra Catmull-Clark subdivision.
Change it back to the default, and seeing as how you're now doing faux caustics, your
Refraction Quality multiplier can come back down. Diffuse can be 0.5, most of the noise
seems to be in the reflections, so up the multiplier on that.

P.S try local BRDF + global point cloud for your SSS model, bleeds into the holes better.

Cheers

Lewie