FYI, I also had to silence a duplicate-updaterc.d-calls-in-postinst false positive in ddclient. The two calls to update-rc.d are in the two branches of an 'if' statement, so it is not actually called twice.
See lines 139 and 149 of: https://salsa.debian.org/debian/ddclient/-/blob/debian/3.9.1-2/debian/postinst#L139 Commit that disabled the lintian check: https://salsa.debian.org/debian/ddclient/-/commit/b65a60e072334f0cee52b41ed4b254bce0d02bad
