Maybe we should call out metafacture-csv-plugin as the "inspiration" (to put it mildly).

Right. It's a copy. I thought to add @eberhardtj as author but I thought the author is hijacked resp. not the original one, because it's somehow ghosted (https://github.com/metafacture/metafacture-csv-plugin) and her github history starts 2019 and it's spares. So I mentioned at least the dnb as first contributor.
Shall I force-push , mentioning the original commiter's email address like the one in 087e20b ?

And also deprecate the plugin as a consequence of being merged into core.

+1 doing this when merged.

but I thought the author is hijacked resp. not the original one, because it's somehow ghosted (https://github.com/metafacture/metafacture-csv-plugin) and her github history starts 2019

Yes, I would probably just use the user name without the @, so no direct connection to the GitHub user is created. But e-mail address is fine as well (or even better) if you got one.

Shall I force-push , mentioning the original commiter's email address like the one in 087e20b ?

Yes, sounds good. If it were me I would also reference the original repo, so one can follow the Git history.

Reworked PR. Please have a look again @blackwinter .

Where is the documentation in https://github.com/metafacture/metafacture-documentation/blob/master/flux-commands.md
or how is this updated? Since @fsteeg said this is automatically created?

The flux-commands.md is not yet automatically updated AFAIK (there is a ticket somewhere ...). I do this regularly by hand at least when doing a release and at best after merging the PR.

I've added the unit test from my #486 (comment) in f3b3d92.

ah - sorry! Amending the commits and force pushing must have lost these. Good that you checked that :)

I tested without options and | encode-csv(includeHeader="TRUE", separator="\t", noQuotes="true") seem to work nicely!

And also deprecate the plugin as a consequence of being merged into core.

Done this, see https://github.com/metafacture/metafacture-csv-plugin/blob/master/README.adoc.