I have long advocated for disabling tpm in bios, uefi-boot raw dm-crypt to even get grub much less init. This is also how I have done encrypted disks in the cloud using dropbear ssh as an initram shim for key/pass entry. Bios boot pass is annoying but required. Watch your acess/auth logs. Run a HIDS. Isolate your procs and especially their network comms. Security is an onion, not that most c-suites have any idea these days, blinded by fast talkers.