Strays a bit from what you asked so ignored if not welcomed, but in case it helps, or in case there's a way to have microblogging posts appear on Lemmy:
Sending RSS feeds to bots such as @birb@rss-parrot.net or @owner@rss-mstdn.studiofreesia.com should give a bot profile to follow a given feed's updates. And both should be usable from pretty much any Mastodon instances, making the potential usable instances much broader. Two small things to note however, first the Studio Rafflesia's bot's usage rules are in Japanese so potential language barrier there, and second and confirmed by the author, sending a feed to RSS Parrot through Mbin doesn't work.
Other than that, and in line with the question, I second !meta@ibbit.at.