what is the Maximum eMMC memory size for PE-HMi1

Hi,  We are in the process of making custom board with PE_HMI1 MCU. this board will be having different GUIX screens for User Interface. We already integrated SDRAM and SDCard into this circuit. additionally we would need to add eMMC Memory to be connected into QSPI line. 

I referred PE_HMI1 development kit's circuit diagram. In the diagram, I found eMMC Memory connected to QSPI line with Part number "MTFC2GMVEA".  This part seems to be absolute. we need to find an alternative eMMC memory. 

Please anyone guide me to choose eMMC memory.

what are all the limitations?

what can be the maximum size?