In Blender 2.80 on macOS 10.15.0 the RPR v2.0.150 plug in now supports viewport denoising.
This works for EAW and LWR types of denoier:
However if you select Machine Learning the preview renderer refuses to start.
With final renders the result is the same.
A final render performed with the EAW denoiser:
Verses the ERROR which is thrown on a final render when the ML Denoise is turned on. (The use Color AOV only checkbox setting makes no difference):
All tests performed with Blender 2.80 official on macOS 10.15.0 (SU1) on a MacBook Pro i9 set to use the VEGA 20 dGPU only.
This bug also applies to Blender 2.81 Beta with RPR 2.0.150 on macOS.
GL Interop = True was set for this test.
GL Interop = False is an instant crash for all RPR renders.
Unfortunately it's the same as before on Catalina. It finishes the render and as soon as the denoise process kicks in it crashes out of Blender.
Although with Blender 2.81 support improving the built-in Denoise compositor node does a fine job anyway.
All Final Renders work great on Catalina. Preview rendering... with any setup, with any devices, is extremely crashy - completely random as well. I know it's an unsupported OS so I'm not going to post any issues because they may well work fine on Mojave. Everything else works for me on Catalina so I'll wait for RPR support for Catalina to be added in due course and then I'll test and debug again once preview rendering is as reliable as final rendering is now.