I'm working towards the platinum and just did my first playthrough. If anyone wants to drop their boss souls or boss weapons, I'd be more than happy to take them. It seems like you could just save your game, give up souls, reload the PS+ save and not lose anything. If that's the case, I'd be more than happy to give the souls/weapons right back. By doing this back and forth, we could probably get at least the boss weapons in one playthrough.
I just want the platinum so I can just play through the game without being forced to create specific weapons or join certain covenants.