I wasn’t addressing only you with that statment regarding refunds.
Cycles Performance - I should have done more research where the scene originally came from, but unless I’m missing something, your own share of the file does not have the conditions included, nor a link to the original post, which would help with proper usage of the files. Doesn’t absolve from responsibilty on my end though. Regardless it has been really valueable for testing things (not only for me) out so thank you for making the original file available to the community and permission to use it.
I have no issues with you being in this thread. I generally agree with most of your takes I’ve stumbled upon. I would just avoid this thread devolving into something that online communication usually does.
On diffuse vs glossy. Technically yes - simulating the same thing in general. In practice in Eevee - they behave far too different to be used interchangably. When I was messing around with the initial tests I spent some time on seeing if it was possible to build a ubershader with just replacing the diffuse component with glossy (you can control what glossy BSDF is used for SSR with the order of shader mixing and exclude shaders with convert to rgb, altough that’s a whole different can of worms) and it looks different enough to not be usable as a stand in for diffuse like that. Even with accounting and fixing the difference in brightness. Might look okay in a simple test scene with mostly white materials, but something like skin will not look anywhere close to what it should. I’m still stuck with a laptop for few days that struggles with the default Blender scene in Eevee so no fancy scenes for comparision at the moment.
I don’t have a way to remove world lighting from only two nodes inside the material. So I don’t believe that part is fixable only as a addon. Then there’s the whole low roughness dielectrics thing that also isn’t compatible with hijacking the SSR for something else.