I'm no lawyer or expert on these matters, but I know that Codeberg e.V. is considered charitable, so the people hired by Codeberg should be eligible for this already, I think.

I don't know if KDE e.V. is also considered charitable, but I assume they are, and they also hire developers. I'd be curious to learn how the tax reports in these situations work.

IMO it would be interesting to see those two specific Vereine getting volunteers.