Purchase Request workflow

I am trying to prevent the signature circuit from restarting when the supplier is set or changed. 

Most of the end users will not know or care who the supplier is during the initial stages of the request.  However, the purchaser is required to assign the supplier before generating the order, this restarts the circuit.  In Apres_modif, I see the reference to the GPOINT "APPFLGMGMT", I assume this is where I can make this adjustment, unfortunately I cannot find any documentation or reference to this entry point.  Does anyone have any suggestions? 

Thank you,