I've been through security multiple times before (my daughter left her book in one of the groundside restaurants) and nobody cared. Anecdotal I know, but n=1 is better than n=0

I did this flying internationally. origin to OHare, OHare to philly, philly to London. Had hours to burn in Philly. Took a wander outside for a smoke, couldn't figure out how to get back inside (the layout seemed like it'd make plenty sense in a car, less so on foot, and a trainline blocked the obvious approach). So asked a nice policeman, who directed me.

Once we figured out that it wasn't actually difficult, we repeated once more before we left. Horrible habit I know, but on long flights/connections you spend near on a whole day "airside". It's pretty simple to just explain why you wanted to nip outside for some fresh* air.

Print multiple copies. The boarding pass checker has no way to authenticate them so you could even make fake boarding passes. Going through different checkpoints would not be noticed. Even going through the same checkpoint probably wouldn't be noticed.

If you're a smoker, then not so much. In order to smoke at Heathrow, for instance, I have to go landside (sometimes through passport control) and back, with no problem, sometimes more than once if a flight is delayed for a long time.