Well I don't want to sound harsh, but do it better...
Oh, that's not harsh, not by your standards.
You are right - it could be done better, but the time investment of un-fun days of sitting in front of an Excel sheet crunching numbers is far greater then the net gain in... I don't know? Realism? That's not why we're here.
I was honestly just curious whether it was a conscious design decision to make some things exceptionally hard (or others easy) to manufacture.
But to argue some of the points brought up by other posters:
The only way to abstract superior techniques/tech within the engine is lesser time costs.
But wouldn't the improved manufacturing techniques be offset by increasing complexity of high tech items? I mean - better tools mostly allow making simple items faster. Or large batches of more complex items. I.e. - using modern tools to make a single assault rifle would probably take much more time than it took to make a musket with more primitive tools. Sure, *if* we set up a robotic assembly line we can make 100 ARs in the time it takes to hand-craft a single one. But that's not the scale Piratez operate on.
I mean, if the gals are making the platemail out of plasteel sheets, then it kinda makes sense for it to take so long, while making power armor can be considered mostly just connecting and assembling salvaged power armor parts with armor plating and an helerium battery.
That's why piratez platemail is an opposite example - you have pre-made parts (chainmail) that you just attach plates to. Testudo takes raw plastasteel. And yet the first takes more time. Same for Boarding Gun (new item) >>> Custom Shooty Gun (modification, but more time consuming). The point is valid though - modifications are generally easier than making completely new items from scratch. I think there's even a #XX hint
about it.
With the boarding guns, maybe the gals are actualy handcrafting every single part because boarding guns aren't commercialy avaliable, they're all hand made, and making stuff out of nothing but basic materials takes a while, regardless of how simple it is.
If you haven't noticed, 80% (or so) guns available to manufacture are not commercially available. What makes some non-standard items harder than other, assuming both are made of raw material and of similar tech level and complexity? Besides, while boarding guns are not commercially available, they are available nontheless as Sky Ninjas use them as well.