i have looked at specification of some radio drivers. There are various supported features like CRC checksumming, inline Encryption, changing radio modulation, Datawhitening or fine tuning of parameters.
This functionality needs to be accessible from higher layers when alternative transport protocols are implemented or switching between protocols are needed. My idea is to define an function with three parameters(feature id, in data pointer, out data pointer). If a feature is needed it can be implemented without changing radio API and any radio driver.