[level]

Rather than maintaining a list of HSTS websites which isn't cross-browser, why is there not an optional HSTS flag attached to the DNS response? I don't know anything about DNS requests, so changing the protocol in a backwards compatible way might be impossible, but that seems like a much better way to maintain that information than with a separate list.

[ekimekim]

That would need to be combined with DNSSEC to be useful for security, but with that caveat that sounds like a good idea.