Thanks for your reply.
‘Even if you use productUpdate with inventoryQuantities for the second new Location, this doesn't automatically create an InventoryLevel.’
Perhaps it should? Without automatic activation this turns our product update from a single call into a dialogue. That will in turn have a negative effect on our update throughput.
Fetching every product to check for location activation before each update doesn’t seem very efficient.
It would seem logical that if you push a quantity at a location then you want that location to be activated.