Change for permanent save of attachments for weapons with modified appearance.

Hello, I want to ask about the weapon skins in the game..it's pretty pointless that when you have a skin like the Phantom edition, you can't permanently remove anything from the weapon to keep it saved...you have to remove it before every round, over and over again, every game...it's not worth buying any weapon skins in the future because not all weapon modifications fit everyone..so I want to ask if it's just a bug? Or is it supposed to be that way???