Nonlethal penalty with piercing?

[Some Other Guy]

All of the nonlethal weapons are bludgeoning or slashing. Blade of mercy trait removes the penalty on all slashing weapons and bludgeoner feat removes the penalty on all bludgeoning weapons. Is there anything that removes the penalty for piercing weapons?

[blackbloodtroll]

Merciful enchantment.

Order of the Blue Rose Cavalier ability "Flat of the Blade".

[Benchak the Nightstalker]

Virtuos Creed: Mercy

[blackbloodtroll]

Redeemer Paladin archetype.

Weapon Versatility + Bludgeoner or Blade of Mercy(admittedly, this means doing bludgeoning or slashing with a piercing weapon).