If you're this serious about security, you should be manufacturing your own hardware.

If you're this serious about security, then manufacturing your own hardware isn't good enough, you need to create your own big bang to seed your own planet to source your own helium to be used in the production of your own ICs.

But even then? can you really trust the research and information about how to produce those ICs if you have not conducted that research yourself personally?

I wouldn't trust myself to manufacture my own hardware.

If you're serious about privsec you should use GrapheneOS.