stupid question: timing w/vacuum advance theory, trying to understand.... Options

[Dr. Roger]

i understand that initial mechanical timing is important because it needs to be retarded enough to allow the engine to turn over but advanced enough to start.

i also understand that mechanical advance increases as RPM's increase.

i understand that the vacuum advance hose needs to be disconnected and plugged to time ignition at idle. (no vacuum advance). after timing, the vacuum hose is re-connected.

now where i'm confused is the vacuum advance dials in advance under high vacuum states (idle and mid throttle).
this means less advance at wide open throttle. makes sense so far.

where i'm confused is if i start my car, and do not touch the gas pedal, won't the engine get high vacuum turning over the engine and kick back the starter?