Unfortunately there is no built-in functionality currently available in the TS 2.0 API to programmatically adjust the struct passing property of a step. If this is of serious concern to your project I recommend that you make direct contact with an NI engineer via email for troubleshooting and personalized recommendations as to how to access these settings.
Regards,
Elaine R.
Applications Engineering
National Instruments
http://www.ni.com/ask