USB Dev MSC Example DMA Memory Usage

I am trying to reduce the amount of memory that the USB Dev MSC code uses for DMA. I would like to tune it such that it can use just L2 RAM or OCM. The cppi41dma.c modules uses 219680 bytes of buffers in SDRAM. There are many interlinked buffers (linking_ram0, region0DescriptorSpace, dBuffer, dmaBuffer, cpii41DmaInfo) . The allocation of the various buffers seem almost arbitrary. Some allocations seem outright wrong or random. Has anyone attempted to rationalized these magic numbers? How deep do the buffers really need to be?