Decoding the header

[pjalocha]

I try to decode LoRa header, this is encoded in the 8 symbols which follow the reverse-chirp 2+1/4 symbol part. Can someone confirm that the code in this repository has proper algorithms for this part ?
I have the symbols, but I can't make sense of them after deinteleave.
Do I need to de-whiten then as well ?
Is there anybody knowledgeable here, who could clarify the details ?