Strip signature on reply without standard separator

[Satoshi Yoshida <dynamisxar@icloud.com>]

I use Gnus 5.13 and Emacs 28.1

I want to strip signature on reply without "-- ".
I read https://www.gnus.org/manual/gnus_48.html#Article-Signature
and add to .gnus.el,

(setq gnus-signature-separator
      '(
	"^-- $"
;        "^[ \t]*\\(--+\\|__+\\|==+\\)[ \t]*$"
        "^\nbest\\( regards\\| wishes\\)?.?[ \t]*$"
        "^\ncheers.?[ \t]*$"
        "^\n\\(good\\)?bye.?[ \t]*$"
        "^\ngood luck.?[ \t]*$"
        "^\n\\(kind \\|warmest \\)?regards.?[ \t]*$"
	"^\nrespectfully.?[ \t]*$"
	"^\nsincerely.?[ \t]*$"
	"^\nthank you.?[ \t]*$"
        "^\n\\(many \\)?thanks\\( in advance\\)?.?[ \t]*$"
	"^\n[ \t]*\\(-+[ \t]*\\)?[a-zA-Z]+.?[ \t]*\n*\\'"
	)
)

But I found that customizing gnus-signature-separator
has no effect on reply. I'm sad.

There is a solution by customizng xcite.el.
It's a wonderful package. But unsuitable for my purpose.
Because it needs a little bit more operation,
i.e. delete cite tag "foo > " to "> " everytime.
Additionally, delete "> \n" after "...said:"
and "> \n" before my signature.

For that reason, please show me another solution if it exists.
I can't find it in archives of this mailing list and web search.

I know supercite.el and mu-cite.el too.
But I don't know whether I can customize these package for my purpose.

-- 
Satoshi Yoshida