You need to bring any colour texture into the same colourspace (diffuse, specular colour, etc…), all the scalar components should be omitted though, even if obvious I precise it because sometimes facilities pack many different scalar data into a 3 channel texture and it is very easy forgetting not to transform it when processing things through scripting.
I also read somewhere that in a future version of ACES, the RRT and ODT wlll be separated from each others? I’ll edit this post if I find back this message as I think I saw it on the forum. But not sure.