I suspect that every class 387 is certified with all electrical equipment fitted irrespective of its destination. That is how Bombardier can manage these add-on orders. If a customer insisted that a train was delivered without DC shoes, it would involve the creation of different manufacturing parts provisioning, reduced (i.e. different) test and inspection schedules and changes to deliverable documentation. With sub-order quantities of less than 30 units, the above raft of changes/deviations from the primary production standard would cost a lot more than a dozen sets of shoes and mounting hardware.
On delivery to the customer, there will be a documented procedure showing how to remove the redundant hardware (and store it), make any modifications to the software configuration and partially certify at a new build standard. Given that all of these 387s are RoSCo owned, they would rather be able to return any unit to a more useful DV standard without paying the manufacturer to add the items in as a modification.