Actually any geometry with a Corona Light Material will render as efficiently as if it were a "Corona Light" (with the exception of a sphere, where the spherical Corona Light will in fact render faster and cleaner). Other than that, the Corona Light Material is identical to something being a Corona Light, so any "noise or problems" would be the same if it were a Light as there is no difference in how those are processed/handled.
Thank you Tom for your reply.
So, if I make a corona disk light (or cylinder), and make a disk/cylinder mesh, and add a corona light material to the latter - both will render:
1) Within the exact time frame achieveing very similar results
2) Will give as much illumination
3) Will be denoised within the same time frame using denoiser
4) Will produce exact amount of noise in very similar situations
5) Will give similar amount of gi to brighten up spaces
If so thats actually interesting, not sure why I have read to stay away from corona light material, and rather use corona lights for gi.