Take it to the Supreme Court.
Every time I sign a mortgage, the lender requires me and my wife to appear in person, with mulitple forms of iD, to personally sign the mortgage contract in front of a witness before a Notary Public as authentication and validation that I consent to be party to the agreed contract.
Autopen is akin to someone with a rubber stamp of my signature to stamp my signature upon a legal document without written, signed, and notarized power of attorney.
Laws and contracts require a demonstrable written, witnessed, and notarized chain of authority and authentication to be enforceable.
If someone uses a 'stamp' to authorize an official action without a demonstratble, written, authenticated chain of authority - starting with the US Constitution, followed by Laws of Congress - why should it be considered valid?
Isn't signing an official Presdential Federal action with autopen - not authorized by the US Constitutional and Laws of Congress - identity theft and fraud?
An unauthorized person is assuming the identity of the President and of the Office of the President of the United States to fraudulently authenticate official acts as having been personally authorized by the President, as evidenced by the President's personal signature.
At the very least, if the US Constitution and Laws of Congress allow the President to delegate authorities, shouldn't official acts be personally signed on Behalf of the President by an official with legally delegated authority to do so.