You must not have noticed. The current version of Ishiiruka has depth access. Still does not work with reshade (from my experience, at least) but presumably there is nothing stopping anyone from writing/porting AO/DoF to Ishiiruka's shader framework. I was going to try myself if someone else didn't get around to it.
Hopefully this feature gets brought over to the main builds.
Hopefully this feature gets brought over to the main builds.