What are two items that an administrator should consider when building out a flow for...

When building a flow for multiple locations, an administrator should consider the following challenges:

Multiple locations will introduce nested loops which can make the canvas substantially larger. For example, a flow that handles multiple fulfillment orders per order and multiple fulfillment order lines per fulfillment order will need to loop through both levels of records. This can make the flow more complex and harder to maintain.

Multiple locations can lead to limit exceptions. For example, a flow that queries or updates a large number of records across multiple locations may hit the SOQL query limit or the DML statement limit. To avoid this, an administrator should use bulkified actions and optimize the flow performance. References: Order Fulfillment Flows, [Flow Performance Best Practices]