waltervolpatto wrote:Yes, the idea is to get temporarily out of ACES cc(t) in a known color space, apply a LUT an get back to ACEScc(t)
Not sure what you're going after with the original question of applying a LUT 'as is' but I think any LUT that is designed to work for any colorspace can just be applied in an ACES workflow by going to that colorspace before and back out to your timeline space after with the exception that display spaces can't be fully inverted perfectly but the differences can be minor.
In ACES the ODT+RRT is always present (if you picked one) so if the intent is to actually use the lut to go to display instead you would have to bypass the color management for that clip instead.
I presume the distinction between process node LUTs in AP1 or AP0 has to do with LUT look modifications that might need to be in linear AP0 like the ACES 0.1.1 Emulation. I think that project setting is virtually the same as if you'd change the node itself to ACES-2065-1 but haven't tested that.