Clearly the way to solve that is to "just" (load-bearing word to be sure) include a signed hw manifest attesting which chips were present at manufacturig time and then printing a warning - not refusing to boot.

Surely the problem lying about selling authentic unmodified boards, not the act of modifying them.

"200$ for my custom-hacked Pi. ymmv." 👍.

"200$ for authentic 1TB ram pi, trust me bro" 👎.