Man the grind for boss blueprints is ridiculous.
I have done the Snatcher mission more than 50 times. That I counted was 40, but I've done more runs without counting. The mission is short I take around 50 seconds but after that many tries still no blueprint drop???
20% drop rate my ass.
Edit: I did it. Looked online and you gotta destroy his missile launcher that on the free mission NEVER appears for more than 10 seconds.
Tried online once and lo and behold the fucking thing is out all time shooting at me, and we are not in a tunnel anymore so I can fly freely. Didn't manage to destroy it before killing the boss.
On my second try a japanese dude joined and took the boss practically by himself, including destroying the launcher...blueprint drops.
I offered the guy the Law of Surprise on the chat, I think he didn't understand but I'm going to sleep, whatever I see first tomorrow is his, be it my wife, daughter, dog or breakfast.