I've unlocked a lot of blueprints for guns, and I also have the Battlepass which unlocks even more in the season tiers.
Some of them look or sound cool, but truth be told most of them have trash attachments. And when you change them it makes the gun look more and more normal. It alters the look. I would rather level the guns and use my own setup.
I do sometimes use them just for the name, my EBR is called "Stay Frosty" from the blueprint.
When I kill someone it shows on their screen. "Annihilator","Flood","Dusk" etc. I just hope it confuses them and they don't know what gun it is. 😂