Locations for products are confusing right now because when creating the pick list, the Warehouse Location is used as the location, however, you can also have multiple locations within Inventory Management location for each item -- but this is not an option to show up on the pick lists:
Inventory Management settings within a product, contains a section to add locations:
Warehouse location section within product shipping settings:
Picklist prints Warehouse location and NOT the Inventory Management locations:
If Inventory locations can be a part of the pick list, that would be great!