You just defeated the whole purpose of the slipping stem: to help protect the stem from damage if too much force is applied.
Like when you try to de-cap a Berdan case.
If you're running your press so hard and fast that you can't feel the decapping pin strike something that "isn't right", you need to slow down
Case sorting removes Berdan cases, and head stamps known for tight flash holes.
Clean, sort, inspect. I don't wait for a die malfunction to tell me that I was too lazy to properly inspect my brass.