SFB's Drone 'D' to B rack conversion

What's a Drone rack D in SFB?

Drone racks are usually much like a revolver: there are multiple bullets in a current load and firing the ammunition depletes it. Once empty, you must reload.

.. Drone rack Ds are kinda in reverse. It's like having barrels that can fire from the same magazine... but only 1 barrel per turn. Losing a barrel doesn't impair the operation of the rack.

Conversion

There are no equivalent racks in SFC for the SFB drone D racks. Closest I could figure was to replace the rack to a B rack and lower the BPV by 3.

(Note: I came to this decide on this conversion by comparing the Z-DN and the Z-DND which has Drone D racks.)