#1: Then fine tune your global physics substepping (and optionally the object itself) if you are still tunneling with CCD on and large collision bodies, also you want to make sure that your constraints aren’t TOO stiff. I can’t magically stop tunneling from happening with Physx when using extreme values, you have to work around its limitations.
#2: I am not talking about the swords, I am talking about what is hitting the swords, if it is an NPC then it needs to use physical animations or manual ones that fall back from collision. If it is other players hitting it and you want to be able to block a swing then you’ll have to have the stiffness higher than the incoming swing to stop it or they have to actually manage the hit by deflecting or moving to block at a point close to their grip for more control. That isn’t how physics work in game or the real world where two equivalent forces can collide head on and only one of them is affected.
#3: You don’t need secondary grips at all, just calling another grip on the other hand should work, the melee script automatically manages primary / secondary hand assignments based on the settings you use and applies the seperate constraints that you define.