I know crossposters make transition easier for people who find it hard to completely switch from Reddit to Lemmy, but we’ve been there already in Mastodon and crossposters were not very appreciated because they are basically bots. They allow you to continue using Reddit or Twitter as your main account while you mirror your content to Lemmy or Mastodon.
It’s frustrating for people who actually use Lemmy or Mastodon to find some content they want to interact with and later notice it’s from an unattended account that is just mirroring content from another site so your interactions won’t get any reply because you are basically talking to a bot.
I created my account in Status.net (now GNU Social) around 2009 and later it was switched to pump.io: https://identi.ca/chuso
And Diaspora* in 2010: https://joindiaspora.com/people/4d0aa88b2c174330380001db
Like others, with not a lot success with those early projects until I joined Mastodon in 2017: @chuso