Why captured German destroyers would burden the Royal Navy

Could the Royal Navy have made practical use of captured German destroyers?

Perhaps, but their engines, limited range, heavy fuel use, and electronics would have made them costly and difficult to keep in service.

The Royal Navy might have accepted captured German destroyers if pressed, but keeping them operational would have been difficult. Their machinery was demanding, their range limited, and their fuel consumption high. Their electronics would also have required major replacement because the installed systems were not adequately protected from salt water. The answer adds maintainability and fleet compatibility to the earlier warning against judging their carefully refined design from specifications alone.