Yes, only one tradeble, destructable, not lootable MBP, and more then one - one-off BPs, they can be lootables. MBP working like a core or a key at construction. MBP owner can do all changes with construction or virtual construction in design mode, and can re-save it into MBP for factory crafting and one-off BPs copy taking.
Like a normal car key with reproduction dates.
For gameplay like pirates, better if any player can have a chance to steal, repair and use crafts, but cant make a BP copies for factory production, or copy trading, or design ideas coping (Ctrl+C Ctrl+V).
P.S. Idea with cores is good, but it is an old day technology, we need something more progressive i thinking.