Arun,
Looks like SAP will process only SP and OTP as you have said. If you need to change this behavior:
1. You need to configure these partner functions on your shipment.
2. Use the EXIT_SAPLV55K_021 which gets called immediately after processing the segments to add your required partners.
But before you do this, you need to do some research on why SAP does not process any other partner function. I am sure SAP has a reason. Your functional team might be able to help you with this research.
Vikram.M