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.