A better proposal in my eyes would be a "improved cross-post". Currently crossposts are just posts that link to the other post, thus making two separate conversations and double the spam for people.

My proposal would be for a crosspost to act like a true link to the original, where people wouldn't see them as two independent psots but the cross posting would just expand the amount of people that sees the original. Users that click on the cross posted post are directed to the instance it was originally posted, and the conversations are kept simple.

I guess that to implement this we would need to change how a post appears to people, it would in a way look like a post from community A that shows in community B, but the ID of the post is the same so it shows up once in feeds. Dunno.