- B31.3 do not mention anything about the fact that displacements can be primary
- B31.1 recognize that displacements are secondary, but say that if you have dificulties in segregate this you have to include them with the rest of primary (occasional)- is their choice so i will not comment.

I can not comment the B31.E as it is not mandatory as per B31.3 and I had not studied yet in depth but seems to refer to structural integrity which is reasonable.

In any case we are not mixing codes.