Some engineers would design the additional connection for half the load. Saying the the two ply nailing will add to the strength. Others say to design the connection to transfer 2/3 the load and still use the two ply nailing to help. This is to account for critical slip of the connection between the plies. A few others have said you only need to connect for half the load. I am between the half and 2/3 the load. But it really depends on the situation.
If you are using a face mount hanger, the nails in the hanger do not count as part of this transfer connection, per most hanger manufacturers. Also you need to note that the connection is to be placed half to each side of the hanger.
Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.