It would not prevent duplication, only add grind-time to it.
Theoretically
one could make a 1-dimensional cannon-waffle that moves along a rail and cuts the ship at a layer to get a view on that layer and rebuild it by taking screenshots and have an external software figuring out block IDs. If he paints blocks black/white in custom textures that would be as easy as scanning QR-codes and if he understands basics of starmades data format it would take an hour to make a script putting it together from a list of blocks along each Z-line.
Today, it's not a big treat, but if someone manages to do it, all others feel cheated or think he is the original author when he publishes it in CC and the style-signature isn't easily recognizable for not being his.
It is better that the limit is implanted server-side as game rules rather than against ideological theft, or it may trigger for building templates like rooms and USD.
Like: Ships with "CopyRight" in name cannot be blueprinted or renamed.
(EDIT: the term "CopyRight" should be replaced to represent what the author wants: I prefer if some term is used which allows theft during faction-wars for RP-value. I also do not want to encourage CopyRight but highlight the problems that come with implementing such a feature. For me it was like saying: "You do same shit of the same level as CopyRight on WindowsXP")
[doublepost=1548623602,1548622945][/doublepost]
Let potential buyers have the ability to 'test drive' the ship in a virtual sector (like shipyard uses) from anywhere on the trade network so they know if it's worth buying or some kind of scam.
You buy a small ship you enjoy and if it doesn't hold what the creator advertises in "a youtube video" (EDIT: or display block and testrun) you make him take ship back for sale price or declare him a personal enemy. (EDIT: One example would be unannounced invisible warheads built into reactors that explode when toggling logic more than 100 times)
There can be some tolerance if you got an awesome craft and the new one is a small-scale scam you probably won't do anything stupid, but discussing a settlement.
Perhaps the merchant was baited to selling scam or offers you something to not screw his reputation.
The only thing peoples shouldn't do is let those who sell scam get away without loss.
8-13% of your own reputation should be used like a bounty to flag scammers.
Every time you flag something, the system must balance it on all accounts you flagged, that's why the range of 8-13% is flexible (the system middles you on 10% when you reach one bound)