I've updated debian/knot.service file from upstream which already addressed described issues.
It's been synced in knot-3.0.1-1 debian package release and it remains in sync as of 3.0.4. You can look at commit cc65f515c1: https://salsa.debian.org/dns-team/knot-dns/-/commit/cc65f515c1 I believe this issue is solved and can be closed. Cheers, Jakub Ružička
