It looks like nothing in the sh.itjust.works rules would prohibit this, and for image synthesis specifically there is already a !nsfwai@aiparadise.moe

But I don’t think it’s just about which server wants to have the community. When I post stuff and upload images for the posts, they get URLs on my home server, which is who actually seems to hold the bits, even if I post the post in a community homed elsewhere.