Sure, sorry it was quite late yesterday and I was just commenting quickly whatever popped up.
It looks like I made an error when running through ReFusion. I accidentally left the RGC on on the color pages ODT node so it applied twice.
So ACES 1.3 OCIO RGC works as it should.
Sorry for the confusion!
The way I tested was loading ACES_OT_VWG_SampleFrames.0063.exr onto a timeline and apply ACES Transform on the color page to ACES 2065-1 to sRGB with RGC applied. No project wide color management. Then a copy of the clip running through ReFusion with OCIOColorSpace ACES 1.3 loaded and applied RGC as Look. Then switch off the RGC on the ODT node on the color page for that clip. They should fully match.
If you’d want to test if this works in Fusion Studio you’d need a view transform as well. You could load a second OCIOColorSpace and have it load the ACES 1.2 config.
