@patrickboston that is the case from my testing in Non-PROD environments that it uses the search to retrieve the Entitlements and to apply any Source filtering.
There is additional discussion on this topic HERE where one of the Product Managers chimed in and seems to be saying that faster processing may be an additional purchase option being considered, if I understand their comment correctly. You’ll have to read it for yourself to see if you draw the same conclusion. Or hopefully they will come back and clarify what they are trying to state.