Multiple IB Fabrics on a Single BX5020?

Is it possible to use a single BX5020 gateway to connect multiple IB fabrics to multiple Ethernet networks?

For instance, could I have one IB fabric connected to port A1, bridged to an Ethernet network via a LAG on ports A2 and A3, and a different IB fabric connected to port B1, bridged to a different Ethernet network via a LAG on ports B2 and B3?

Bonus question: If it is possible to do this, how does having multiple bridges affect the limit on the number of vNICs? Is the 1k/4k limit global across the BX5020, or per bridge group?

Thanks in advance for any answers or suggestions,

Rusty D