my suggestions, in no particular order, with varying degrees of seriousness:
-really just mirror your own syntax, but specifically put the BLUF (bottom line up front). i hate when people go "oh my god, i had an emergency!!! [10 minute story]. anyway i'm fine." this could look like some type of relational clause moving to the front of the sentence. and they could nest nicely with your causatives.
ex: "due to the following emergency, i am unharmed but rattled. [10 minute story]"
or: "the food has spoiled. here's how we arrived at this situation [10 minute story]".
related are phrases like "as per my last email" or "following up on our last conversation"
-your greeting could be "do you mind if i interrupt you?" nothing worse than getting ripped out of something you're focusing on.
-be cheeky with your modalities. autistic people dont always use could/should/would in the same way as neurotypical people. you could have some fun here. for instance my first instinct was to say that you *should* make your greeting what i suggested.
-the word for bright and painful can share a root if it seems appropriate. photosensitivity is wild
-does pitch, tone, or other voice quality encode any meaning? what do autistic people do when they're speaking this language and they go nonverbal? is there a sign language to accompany it? food for thought!
-and lastly, give the pronouns optional marking for how big their meat is, or how loud they're being, or how drained they feel (or make the speaker feel).