Ahhh. I hadn’t checked that forum in a while. It looks like we are the only people that have much interest in this.
I have a home IOT system using MySensors code: https://www.mysensors.org/
It is done in Arduino because the whole idea is it is supposed to be accessible for beginners. They have support for RFM95 and SX126x radios, among others. So it seems like it would be easy to adapt for the LORA-E5 if subghzspi just worked with the Arduino SPI library.
I’ll keep looking for a solution and report if I find one.