I use PhysicalSurface 99% of the time, which is the same as CycleSurface, its just Cycles nodes combined into an easy to use setup, which is very appealing to me, The only time I use the actual CycleSurface are for some specific materials where I think its slightly easier to use. PoserSurface I only use for Firefly.

The materials are created for PBR.

I don't know if its one of those Superfly things :D So I tried changing some things, so for instant setting minimum bounces to 250000 and maximum bounces 500000, Diffuse bounces and Glossy bounces to 150000 each. Based on the tooltip the higher the settings the longer the render time. Now with these insanely high settings, I would assume that the render would never be finished, since I have a fairly low end computer. But instead it have near to no effect on render times, if any. As if they are completely ignored. The diffuse bounces have an effect as shown above, but whether its 1 or 150000 is of no importance apparently.

I know what the min and max transparent bounces does, and why there is even a min setting for this im not sure, but the rest is a bit of a mystery to be honest and can't seem to find any explanation to what exactly they do, are there any logic to these settings or how they work, if at all?