An obvious optimization to that process is having voters fill out an optical "scantron" ballot, then run the ballot thru a scanner and lock the paper ballot awa

An obvious optimization to that process is having voters fill out an optical "scantron" ballot, then run the ballot thru a scanner and lock the paper ballot away for later spot checking. You can network the scanners in whatever crude or advanced way you'd like. This is what Wisconsin has done for about a quarter century.