Corona is proudly cpu base !?! does not have out of core ?!?!?
Although immaturely asked, it's still a valid question worth answering:
CPU and GPU out of core approaches are vastly different.
When VRAM is full, you can offload part of the data set onto RAM and let the GPU work from that set of virtual memory.
Once you go to CPU and you RAM is full, you don't have a RAM 2.0 you can offload to. The only option is slow non volatile memory types, which all require some kind of trickery and hacks not to completely cripple performance. You could make the argument, that Windows Paging is already some kind of out of core rendering, but as you see, offloading everything naively, is awful.
So you need some kind of smart algorithm, maybe camera cone based, or culling based offloading, whatever you can think up, combined with some smart tree cache file you can draw from in a smarter manner than let's randomly throw data onto disk and pray it's the right one.
Anyway you go, you will get a substantial performance hit and thus this is not a priority. Furthermore with CPUs you have the option to upgrade RAM, with GPUs you are stuck. What is vital for GPU renderers to even have the possibility for large scale rendering, is merely a feature of many for CPUs, overshadowed by more important things.
And you are right in some form guest_guest, a large part of the early corona adopter crowd work in ArchViz and their voices for features were heard louder, then more exotic features. The feature request subthread is there for a reason.
