The blueprints having an advantage were all Warzone based as far as I know.
Some others ones had slightly better iron sights for certain guns, for a horrible LMG or AR.
Not exactly gamebreaking, but they had this formula the past few years J4MES was on about.
New gun released OP, then some people being impatient or not willing to grind 3x slide kills in 15 different matches. They will buy the blueprints, then 5-6 weeks later the gun is castrated and nerfed to the ground making it a disadvantage to use. Rinse and repeat.......
Also for people that didn't own Cold War, Vanguard etc and their new guns were released that were OP, it kinda forces the Warzone only players to buy the blueprints or end up buying the full game to get access to the guns.
Also a standard gun that got hugely buffed for example in Vanguard, you ain't getting it without the game.
I'm not THAT upset, but the manipulation behind the scenes is disappointing and very transparent.
It's money over quality, SBBM over connection.
Content is slowly drip fed and held back for future seasons, things like more maps we could of had at launch.
It's all about the money, eventho it's a business and they are hitting bigger sales/targets than ever before.
It seems it's never enough.