Anti-aliasing gone in composite?

I’m working on some credits and I can’t help but notice that the composite tends to undo any anti-aliasing settings in the Render panel. I tried hunting and searching around Blender and online, but couldn’t find anything related to my problem.

Composite render without AA:

Render with AA (gotten by letting it render, then stopping after it starts compositing):
(Those are probably hard to see - an actual render should be done to see the difference.)
Is there any way to preserve the AA?

(Also - indeed, there is a problem with the defocus node causing some unwanted blur, but after trying many things and searching around it seems that there is no solution to the problem, since the defocus node is somewhat buggy in behavior. Any help is appreciated!)

If you are using FSA, then any change in the compositing setup will remove the AA, you will need to render it again to get it back.

If not, then can we see a screen of your setup, because it might be due to how you setup certain things like mixing and I think there’s various passes that might give trouble to the AA filter as well.

Oops, I forgot to upload my blend:

Template-PACKED.blend (583 KB)

And nope, not using FSA.

Bump - any ideas?