I've never used it, but this might be a relevant discussion by @jpmeijers and @platenspeler:
The communication with the radio is done via SPI, which is a bus. Do you think we can add two more radio's to the same bus, using the two free pins as chip-selects?
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I think it will be a major change in the software to keep track of all extra administration. Not only the DIO0 but also the slave select line is in general duplicated for every slave on the bus.