Generally we’d say no, not really, and certainly not with the highest security.

The whole point of a security key is that it is supposed to be impossible to extract the key material, that simply isn’t going to be the case for a DIY solution. They have shields, and light sensors to prevent decapping/forensic inspection.

Recommend taking a look at this: https://duo.com/labs/research/microcontroller-firmware-recovery-using-invasive-analysis