I would actually suggest that a modular supply chain cuts long-term costs due to the expenses related to on-demand repairs. If the parts are available, you would just swap out the modules and go; damaged modules get sent back to the manufacturer or other third party for repair or recycling, thus re-entering the supply chain as a fixed component (at a discounted price compared to new module) or as raw material for new module production. Since module repair becomes somewhat independent of ship repair, the time that a single ship needs to spend docked is reduced - arguably the most valuable result for the Bretonian military.
That said, the Firefly has not been manufactured by the Bretonian Crown, or by a Crown-owned corporation. Provided that the design doesn't use parts only available in Bretonian factories, then the supply chain for associated repair materials would experience a degree of independence from the effects of the war (but not total independence - wars tend to have knock-on effects).
Croft, the infocard should avoid being too specific about turret placement and arcs, since they could potentially change in the future.