ACES has issues. Not the least of which is that it began life as an archival format. When CGI folks tried using the primaries for rendering and graphics work, it was discovered that wide gamut RGB primaries can lead to pretty poor rendering characteristics. Which is what led to ACEScg.
That is, ACES is nothing much more than an overly complicated REC.2020. The jury is still out as to whether or not everyone will get on the train, and it’s rather fractured.
The main bit of ghastly from ACES is that it does only a brute force gamut mapping. That means that at high intensities, the colours clip and skew just like sRGB. Further, the gamut mapping from the wider gamut REC.2020-like primaries of ACEScg are brute force absolute colorimetric mapped to the smaller gamut, which also leads to not super aesthetics.
Spectral of course is most certainly the future, but it too doesn’t alleviate the need for aesthetic gamut mapping in the camera rendering transforms.