i use a yubikey and still have the ability to type my LUKs password in. Yubikey is just more convenience: plug in and it auto type the password field. On Fedora this means it populates the field with asterisks. Still, i think using password is the best method.

With that said, i believe a much better secure layer is something similar to what Novacustoms, Purism attempt to do: verify if somebody else not you try to access the laptop. So far i know of only Dasharo boot and the stuff from Purism that can do these…