Especially anger! Don’t be afraid to program “fuck you” into an autistic person’s iPad, don’t be afraid to teach sign language swear words and don’t be afraid to make up PECS cards with a little shit pile emoji.
Teaching an autistic person to tap “fuck you”, sign “asshole”, or hand you the “shit” card to tell you they’re pissed off may be one thing that stops them before they start punching or biting. Because if they can strongly indicate they’re pissed off, you can say “okay, let’s talk about this” and ask them questions (even if they have to be simplified to yes / no) get to the root of what’s making them angry.
And that means you stop and discuss it if they start using swear words, because swearing will mean they’re having a strong reaction to something.
I think it’s worth the risk of them tapping “fuck you” in church, signing “asshole” at the grocery checkout person or showing their grandma the “shit” card because at least they’ll have an outlet for their feelings that don’t include drawing blood or leaving bruises.
There’s a big emotional difference between “this is bad” and “this is bullshit!” and AAC should be reflective of the autistic person’s emotional state– especially if they have difficulties showing it or their body language / facial expression doesn’t always reflect their actual feelings.