As you’ve already realized, the SX1308P doesn’t NATIVELY support LoRaWAN, so it’s likely that few on the ChirpStack forum will be helpful.
That is, if I read your question correctly, you want to write your own “ChirpStack” software that implements some protocol other than LoRaWAN. That endeavor is unlikely to have support outside the OEM’s forums for SX130x.