How about secure elements? Is any of these SoCs protected against just reading out its flash contents through a debug port or desoldering a flash chip from the PCB?
Odudex can correct me if I am wrong, but I think everything is erased from Krux once you turn the power off, so there is nothing to read and copy.
Than you have to load seed phrase each time you turn the power on, best with QR code scan, but it can be done manually.
That is why they don't need to have or trust secure elements.