How does a push-to-start engine’s electrical system deal with the several functions of a standard ignition switch that has a spring that returns it to “Run” position after you turn it to “Start”?
Some things an ignition switch does:
Off position: power only to circuits that don’t pass through the ignition switch. Typically this means the headlights, parking lights, brake lights, interior lights and horn work.
Accessories position: power to much of the car, but not fuel pump, ignition system, starter.
On or Run position: power to all the above
Start position: power to ignition and starter; possibly momentarily no power to accessories