I don't/won't use Barnett clutch plates. Their fibre is used is to minimize slippage in racing conditions, the Barnett's are hard on transmission gears. The action is much more direct, not a smooth gradual release. I only used a set once and took them out soon after i installed them.
Unless the steel plates have been really overheated, causing warpage, as Mark says, they're not warped, the can be used.