Pierre, According to the sponsorship documentation, it is the sponsor's responsibility to manually close the RFS bug, not the sponsoree via debian/changelog.
https://mentors.debian.net/sponsors/rfs-howto/ I'm sponsoring this now, so I'll close this bug in my next email. Could you please open bugs for your other concerns? Hopefully, they can be fixed in future uploads. Debian Bugs unfortunately doesn't automatically copy the original bug reporter on replies to bugs, so please try to keep the original bug reporter in the To: or CC: line. They might not have seen your replies! Thank you, Jeremy Bícha