Hi. I just used MySensors library with the iBoard without any HW modifications. All You have to do is to edit utils/RF24_config.h.

uncomment the following line:

#define SOFTSPI   // Requires library from https://github.com/greiman/DigitalIO

and modify SOFT SPI PIN definitions to

const uint8_t SOFT_SPI_MISO_PIN = 6; 
const uint8_t SOFT_SPI_MOSI_PIN = 5; 
const uint8_t SOFT_SPI_SCK_PIN = 7;

And it all "just works" ;) Of course you have to have the DigitalIO library, too.

If anyone is interested in trying out the implementation using UDP packets sent to the subnet broadcast address, check out my pull request https://github.com/mysensors/Arduino/pull/66