Yes AP, as mentioned before are signed by a real pen by a machine. So, just like an authentic, if they get put into an envelope too quickly after signing or get something placed on top of them, or get rubbed, the the AP'd signature will smear or smudge.

Yes AP's can smudge as they are signed in real ink by a machine.

I believe APs can smudge as well but correct me if I am wrong.

Is it possible for autopen signatures to smudge? Or is that a sign they're real?