So I've been looking into how various mods interact with Nexerelin's mining mechanic, and it seems like you've manually assigned mining strength to ships that have mining beam nodes, rather than giving the beam nodes themselves a mining strength. All well and good, but currently the Sturmovik (S) doesn't have any mining strength when it seems very much like the sort of vessel that would have some.
Mining Beam Nodes have been removed for the next version, so this is a non-issue. Regardless...
The Sturmovik (S) wasn't given a mining strength because it wasn't designed as a mining ship, but rather a post-battle salvage vessel (unusually specific, I know, but that's its lore). Admittedly the choice of Mining Nodes on it was a bit silly. It still makes a good mining ship since it can field a wing of Mining Pod drones and a Mining Laser or Hammer Torpedo rack, but it isn't able to function as one inherently - I have no intentions of changing that at this point.
Also, considering its name and surrounding fluff, have you considered asking King Alfonzo if you could use his "Junker" mechanic from Hazard Mining (wherein ships gain OP the more d-mods they have) for the Junker-class gunboat? :V
With previous versions of the Junker, I may have considered this, but much as I enjoy the concept of "junk ships" I agree with the philosophy that they don't make a great deal of sense in Starsector, as far as "how are ships built" goes in the lore and therefore how they show up in the campaign.
The current version of the Junker is named affectionately more than practically - it's built to code, not from scrap, it just happens that the assembly process uses cheap, readily-available and low quality materials to make a ship that costs about two cents and only barely holds together... Kinda like certain Soviet vehicles in WWII.

(Hint: Build them in bulk, and treat them like slow Hounds with bigger guns.)