Curio gameplay variety is pretty low, as they all in one way or another just increase your durability. I think curios having the ability to boost crit chance as their primary blessing would be really interesting, instead of just more wounds, toughness, or health.
I think a balanced amount for the max amount of crit a staff could give would be 3% or so, so if you manage to stack 3 it gives 9% crit chance which is great, but you give up a lotta durability in return.
This could easily end in another rich get richer scenario as awesome as it would be, because of the abundance of high crit rate weapons in this game. Like the executioner dagger’s 20% on lights. Even though other weapons like the thunderhammer would benefit without being overpowering, or ogryn’s clubs would feel like the same because of how flat their crit bonus is already.
It’s deliberate, they haven’t put any offensive perks/properties on curios, and I don’t think they will because of the stat stacking. V2 railroaded you on what stats you could have per slot.