How do we hookup an antenna multiplexer to the Simultaneous RFID Reader (m6e-nano)?

The Jadaktech datasheet mentions that the m6e-nano can be hooked up to a 4 channel antenna multiplexer? Has anyone done this? What are the power considerations? What gpio pins in the sparkfun board should i connect the multiplexer (e.g. skyetek/skyeplus mxu 4 channel) to address the antennas.? Is it the pins labelled GPIO1 and LV2?

Did you ever figure out how to do this?

Cheers

I would also be interested in if this is possible!

Thanks