I simply want to disable anti-aliasing on an individual basis, for a particular entity, object, or material. I do NOT want to change the global r_AntialiasingMode. My question is: is it possible to disable anti-aliasing for a particular entity, and how would I do it?
No this is not possible. Antialiasing (SMAA/FXAA/TXAA/TSAA) is done in post process so the entire frame is being processed.