An employer is unlikely to waste time on deep candidate analysis. If they see you as a public code contributor, it's an upside in activity, experience, and conversation starter, and discussion points for any interviews. If they look at your code, it won't be deep. I doubt they would go through the effort of correlating from a public coder profile (e.g. on GitHub) to a Lemmy profile and then look at their posts.

Once they're at the point where that would be a reasonable investment, they already know you personally and don't care about online content anymore.

Maybe some big companies use online analysis tools though.

Anyway, I know what I'm worth as a developer/an employed. I don't think I post that kind of divisive or sensitive stuff that does or possibly should be related to my employment and work. If they see it as such, then I'm fine with it not being a match.

I actually think the public nature could and should be upsides. Related to work or not.