How to erase/wipe all ext4 metadata, not just the filesystem signature 53 ef?

I want to make zero all bits of a partition where an ext4 filesystem structure existed (superblocks, metadata, journal, etc), not just the filesystem signature deleted by wipefs. I can quickly zero out files content using shred utility, but not the metadata. On block devices supporting TRIM/DISCARD, this is easy as I can quickly run blkdiscard on the entire partition. However on large rotational HDDs where TRIM/DISCARD is not available, making all bits zero either becomes a large time consuming process or implies destroying/regenerating the disk encryption key (on self encrypting drives) which implies losing entire drive, not just the ext4 partition. Other than reading mke2fs code and creating an imaginary wipe2fs tool based on it, is there already another way to quickly wipe all ext4 superblocks/metadata?