Ah, I just ran into RP002-1.0.1 (which, so far, I had not even bothered to open as I figured one should use specific versions, such as 1.0.2 rev B for TTN), which is indeed very clear:
3.1.2 LoRa™ settings
In order to be fully compliant with LoRaWAN, an end device SHALL configure the LoRa™ physical layer as follows:
