If I understand this correctly, this is not true CSMA, as the transmissions are inhibited by noise and not signal. It would seem like a better idea if transmission was only inhibited by a signal matching the current LoRa modem configuration.
In shared unlicensed spectrum, all "users" must accept interference. There is probably no real motivation to avoid transmitting over "foreign" signals (LoRa or other modulations) that produce some level of energy in the receiver passband of the LoRa transmitter.
Furthermore, the blocking signal might act as a "hidden transmitter" and only be detectable at the LoRa transmitter's location and have no affect on the SNR at the LoRa receiver's location.
I'm not sure if such an alternative mode of operation is plausible. However, I would like the option to choose whether or not the listen before transmit mode is used, either in a fashion similar to the ability to set a socket into a blocking or non-blocking mode, or as an optional parameter to the socket send() call, for raw LoRa sockets.
Come to think of it, perhaps I should have suggested this as a feature on github, but I've already typed it here, so I would be interested in any thoughts on this.
Update: feature request on github is here.