For future reference, 'xartutil --erase-all' in Terminal in macOS Recovery erases all data in the Secure Enclave, including the keys used for disk encryption. I

For future reference, 'xartutil --erase-all' in Terminal in macOS Recovery erases all data in the Secure Enclave, including the keys used for disk encryption. In that way, it can be considered equivalent to a secure erase command on a non-Apple SSD, except Apple can be trusted to have implemented it properly unlike normal SSD vendors who have been caught implementing it as a NOP. Also, in my experience, Apple does not require returns to have a working OS installation. You can erase and return in that state.