I think @Lycle_Park may have an emonPi using the LowPowerLabs library. See Undefined node list up and How to emonhub full reset the emonpi?
As for emonHub supporting a LPL native packet format, that is do’able and probably preferable to trying to get one entirely backwards compatible protocol working ie running LPL in JeeLib compat mode in RF12 compat mode for a rfm69!