Glad you mentioned "software that flips votes," which is even a more serious cheating trick than "early voting", because it potentially can cause a greater numerical change in the vote count in the fraudsters' favor. Judging from the unexpectedly large differences between the pre-election poll results from generally reliable pollsters like Rasmussen and Gallup and the tabulated results in swing state after swing state last November, it would be reasonable to say that "vote flipping" via electonic hacking into optical scanners and touchscreen devices was done to an unprecedented extent.
There are a number of different dimensions of election fraud and cheating whose cumulative effect was so strong in November that it likely turned the presidential race around. Early voting leading to multiple voting was one problem, electronic hacking causing "vote flipping" another. Early voting can be outlawed by legislation; electronic hacking and vote flipping can be nitigated by more careful surveillance on the devices by knowledgeable computer professionals, as you say. Any serious attempt to tamp down on the cheaters must address both problems and even more. We must have the determination to do so or else 'Rats will be in the White House in perpetuity!
And make no mistake about it, the fraud and cheating were targeted to populated 'Rat contolled cities and counties in the swing states where it had maximal impact on the outcome.
The solution is to gather the voters together on the appointed day and have them raise hands to be counted.