Need a bit more information on what your pipeline is. Are you compositing frames from 3D software, applying effects to camera footage, generating synthetic motion graphic overlays...
ACES in After Effects is "possible", to varying degrees of the definition of "possible". You basically have to disable all of the ICC-based Adobe color management stuff, switch the project to 32-bit linear and use multiple OCIO adjustment layers to send all of your working layers through the IDT (and back out through the ODT/RRT so you cna see what you're doing), and finally check your outputs in something that understands ACES (even if you think you've set the project up right the exports can go wrong, and that will stuff it up for whoever is downstream in the pipeline). It's nowhere near as simple as it is in Nuke, Fusion, etc.
Also important to note that while an entire production can be ACES2065-1, CGI is almost always done in ACEScg. It's just better at dealing with passes and synthetics. A smaller gamut but the missing bits are largely irrelevant.
You can also (with significant limitations) work in Rec.709/Rec.2020 and shoehorn the output into ACES color space. Someone tried that here.
The problem is knowing when your software path is legal (i.e. acceptable within an ACES pipeline, which forbids certain things) and the results are legitimate (i.e. the colors match the real scene and are reacting correctly to what you're doing). For example if a background plate is tagged with the wrong IDT, it will have a gamma shift - often enough to make it not match the original, but not enough for it to look "wrong" on your AE monitor (which is not going to be color managed). The same will happen to a texture used on a 3D object, or an HDRI environment map. Some 3D rendering engines can output ACES-legal data, some cannot (Arnold in Maya...brilliant. Corona in Max...roadkill)
Sitting in splendid isolation in a production pipeline you would never know if something is a few percent too green, which is why it's really important to have vision of the steps either side. If someone says your files are "not displaying correctly" you need the tools to analyze them. Maybe the colors are off, maybe it's just a metadata problem. Maybe someone gave you the wrong IDT. In After Effects everything has to be set up manually in OCIO so wrong choices will not throw error messages.
When anyone's starting on this road, especially if they're stuck using Adobe software, it's important to build an in-house pipeline to run loop tests, be that with BL/Nuke/Resolve/etc.. Push something round in a circle and see if it matches itself.
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