This is recommended in the DNS flag day 2019 and we can easily add this to the configuration.
https://git.ipfire.org/?p=people/stevee/ipfire-2.x.git;a=commit;h=3bf804e83400c87398950526170b3d77bf38b8a6 https://git.ipfire.org/?p=people/stevee/ipfire-2.x.git;a=commit;h=372576e0ab699a188e9248d73afcc00a5a635d2b
https://blog.ipfire.org/post/ipfire-2-25-core-update-141-release