The govt should write themselves a virtual printer that would take in the data stream and output a PDF made of individual images. A typical print-to-PDF virtual printer, but government-sanctioned, and they could also make it do something like store the document in an audit database or whatever, just to give people a strong incentive not to skip it or use anything else.
It does open another risk of nation state style attacks that compromise the virtual print driver in a manner that it does not redact information, or encodes 'hidden' information into the format of the document. That seems easier to do with a digital print driver than with the messy digital to analog conversions that occur in a scanner/printer.
That would be interesting and not hard to setup. Install cups on some box, definitely not the host containing sensitive info, and you have a limited, auditable outbound channel.
