@evs@social.lol You should be able to cross post from Mastodon to Lemmy by tagging the community name. Replace the ! with @. But in my experience, this has been spotty with Lemmy.
Piefed, however, can consistently cross post from Mastodon and has not failed me yet. Which is why I prefer Piefed over Lemmy. That and better moderation tools and community portability.
