This is why FDE is mostly the default on all of the devices you mention. The secret keys are stored in the TPM or equivalent. Most SSDs for Mac/PC also have an

This is why FDE is mostly the default on all of the devices you mention. The secret keys are stored in the TPM or equivalent. Most SSDs for Mac/PC also have an OEM software option to trigger a secure wipe using special software from the vendor. The problem here is that the Echo is closed so those options aren’t available to you. However, this is also a problem on other custom devices like printers.