FX3 Sync Slave FIFO 5-bit

Is it possible to use less address lines? I don't need 32 logical sockets so there are two options:

1. Pull down A4 and A3 through resistors

2. Decrease number of address lines in GPIF designer and use GPIO25/GPIO26 as IOs

Second option is preferrable 'cause it provides less pin utilization.

Expected result is to have 4 threads with 2 physical sockets each

Thanks