Implementing a security vestibule exit scheme seems like it would have some interesting ramifications for emergency egress requirements compliance. I suppose that alarmed emergency exits would still be present and deter casual five-fingering which seems to rely on perps not drawing excessive attention to themselves. But the smash-and-grab crowd will still be able to abuse them.For a good-quality jewelry shop or bank, for example, it'd certainly make it vastly tougher to forcibly enter en masse or forcibly remove products. Can apply to entry and exit. Make your purchase, get double-checked at door #1, get authorized to enter the "choke point" zone for exit through door #2. Some customer might certainly whine about the supposed delay, and some might even whine it's an affront and insult, but it's the shop's product and the shop's security, and they've also got a responsibility to ensure customers are protected and the riffraff remains incapable as possible of damaging the shop/inventory/customers.
Last time I was in a jewelry store it was a specialty place specializing in accessible vintage stuff and their process involved securing merchandise not being actively shown. No glass displays - you either saw something online you wanted to see or dropped by and asked to see [style/genre] products - and seemingly a staff very conscientious of a manual specifying some general value limit being shown at any one time. The spendier items were also seemingly shown in rooms off of the main lobby/showroom, likely with discreet maglocks should something worth five figures not be accounted for before sale or the prospective customer departed; the main door looked to have a similar arrangement.
Banks also seem to have not only less cash onhand than in decades past but it's also largely internally secured - either in drop safes for receipts or armored cash dispensers whose dispensing is coupled to account withdrawals like an ATM. These factors - alongside the diminishing role cash plays in daily life - has seen the haul from bank robberies trending down.
I've noticed that in larger stores there's a tendency to have an awkward confluence of entrance/exit area, to the consternation of their LP folks and overt security. 'Super' Targets and Wal-Marts alike have entrances at the extreme quartile boundaries where the traffic flow doesn't completely co-mingle but there are the likes of customer service, restrooms, rented spaces, themed merch sections, offices/break rooms, etc along the front wall with a pathway along checkout outflow that results in turbulent flow.Other than the design spec for the entry/egress area, along with a variant of surveillance and procedures that'd go along with such a thing, it's hard to see a major downside.