I have a unique requirement that keeps cropping up - tracking of specialty tools sent to technicians

The scenario is this: The customer has these specialized tools that are required to perform certain jobs. The customer, once it’s realized those tools are required for that job, will ship the tools out to a technician. That technician may use it on that 1 job or a few during that timeframe. Once done, the tech has to ship the tools back so they become available to others. 

Based on this, I was thinking of several different scenarios:

1) Using Bookable Resource of Type = Equipment. I was thinking of extending that record to indicate the following:

• Current location (warehouse or resource)
• Tracking entity…tracks the shipping to/from a tech. Once it’s shipped out to a tech, the Equipment becomes unavailable. Once it’s shipped back and confirmed all returned, it’s location and availability is updated. 
• Having that specialty tool show up on the schedule board as UNAVAILABLE or AVAILABLE depending on if it's assigned out

2) Setting it up as a Product inventory item and extending functionality to include possible serialization

• Utilizing Inventory Transfer to transfer from Main warehouse (Source) to Destination (Tech/Truck) warehouse.
• Extending Warehouse Entity to include Warehouse Type field, and if Warehouse Type does not equal Facility then expose Bookable Resource field (should be limited to User Type)
• Extending Inventory Transfer entity to include Ship Via, Tracking Info and a Transfer Status (Initiated, Sent, Received, Cancelled. In this scenario, the inventory would NOT be transferred to the destination until it's marked as Received.
• If Cancelled, the inventory is not transferred