@Thomas: If we standardized default join channels and DR by region, then a deployment could get off the ground inexpensively using single-channel gateways. They would implement the LoRaWAN spec and be compatible with TTN, just they would not support ADR. When the time comes that that join channel is gets congested, it would pay to upgrade the gateway(s) to multichannel models.
The question is, would single-channel gateways hurt TTN in some other way?