A retail door that is also the delivery entrance, the refuse route and the staff entrance is being asked to do the work of four doors. In an ordinary retail strip that load is spread; here it is not. Ironmongery specified for a customer entrance gives out inside a twelvemonth under that combination, and it goes quietly — the bolt stops seating rather than anything snapping. Bringing it up to a proper commercial locksmith standard is the only lasting answer.
So the specification on this street should be heavier than the shopfronts look like they need: commercial-grade cases, closers that can be adjusted rather than replaced, and keepers that can be reset as the door settles. Given that there is no second entrance, the cost of getting this wrong is a closed business for however long a repair takes, which changes the arithmetic considerably.
At the harbour, the requirement is corrosion resistance above everything. Gear stores, cold rooms and equipment lockers sit in permanent salt, are opened at unsociable hours by people in a hurry, and are almost never serviced. Marine-grade padlocks and sealed mechanisms cost more than the alternatives once, and considerably less than replacing ordinary fittings every season.