Delay messages and Lower Priorities

I have been requested to delay messages returned from Horizon Passport(MPI) that get sent to the downstream systems as ADT_A08s.  I have a thread 3b1 that sends to 3 systems.  We’ll call them a, b, and c.  a and b get the ADT_A08 messages.  We want to delay these but not hold up the queue for the destination threads.  Thread c we just want to send, no delay.

I am assuming that lowering the priority allows other messages to continue past these messages and then dely them for up to 60 seconds  would allow the original message to get to the destination system, efore being followed up by an ADT_A08 for updates to the PID2 field(HNE number).  Any thoughts.  I am on AIX 5.1 and Cloverleaf 3.8.1P rev 4.