A backup that has never been restored is a hope, not a backup. The routine here is a nightly snapshot plus a monthly restore of one random directory into a scratch path.
restic backup /srv --exclude-caches restic forget --keep-daily 7 --keep-weekly 4 --prune restic restore latest --target /tmp/drill --include /srv/app/config
Compare the restored tree with diff -r and write down how long it took. That number is the real recovery time.