Can you give a quick explanation of how Location.pick_priority should be used?
Our interest is in designating a handful of locations as the preferred place for orders to allocate if inventory is available. If that is the correct usage, is 0/1 the highest or lowest priority?
Yes, Location.pick_priority is intended to influence which eligible location/bin ShipHero should prefer when allocating or selecting inventory for picking.
Lower numbers have higher priority. For example, a location with pick_priority: 0 will be preferred before one with pick_priority: 1, assuming both locations are eligible, pickable/sellable as required, and have available inventory.
So for your use case, you can set the preferred locations to a lower value, such as 0, and leave normal locations at the default priority, currently 1.
One note: pick_priority is a sorting preference among eligible locations; it does not override inventory availability, pickable/sellable rules, lot/expiration rules, or other allocation constraints.