I'm not sure if Crew Chief changes anything because they do some deep fundamental changes beyond just "mods" like flatspotting and such so I have no idea if they did anything with graphics but, assuming things still act like normal, you just enable AA from regular Nvidia Control Panel and, Nvidia Inspector if you want to use Sparse Grid Supersampling. A lot of people recommend using the Diablo 3 AA profile flag (near the top of NV Inspector).
If the AA isn't applying, you may need to check "Disable fullscreen optimizations" (right-click game's EXE). You should generally do this anyways as fullscreen optimizations can lower framerate, cause stutters, and add input lag compared to running the game in full-on fullscreen mode. Optimizations is a deceiving word as Windows is not optimizing anything, it's just making the game run more like it's in Windowed mode.
I read, with Win 11, you don't want to disable fullscreen optimizations as that can cause issues due to Win 11 handling things completely different. I have no clue if that is true or not but with anything pre Win 11 (eg. Win 10), I highly suggest disabling fullscreen optimizations.