I also "wait" for the idle to settle. Get in, start the car, belt up, check mirrors, adjust HVAC/seat heaters, adjust radio/pick song. Takes less than 30 seconds, and by then the idle has settled.
On the other hand, my wife's always done the "start it and go" in her 2006 Civic, even in the dead of winter (-35c). She bought it new. Every time she does this, the auto transmission bangs into Drive. 14 years later, the drivetrain is perfectly fine. Maybe her car is the exception - all I know is that I would never do that in any of my cars lol.