SF12 in US band

[conradholt]

I'm trying to perform a range test using the US band, but I am not able to set SF=12, it caps at SF=10. Now, I'm following this table for the DR configuration, and I'm using the modem.dataRate(8) call.

DataRate Modulation SF BW bit/s
0 LoRa 10 125 980
1 LoRa 9 125 1'760
2 LoRa 8 125 3'125
3 LoRa 7 125 5'470
4 LoRa 8 500 12'500
8 LoRa 12 500 980
9 LoRa 11 500 1'760
10 LoRa 10 500 3'900
11 LoRa 9 500 7'000
12 LoRa 8 500 12'500
13 LoRa 7 500 21'900

There are multiple issues, such as DR is reset back to dr=0 every time, and that the only way to modify the dr is by enabling the ADR capability which is still don't understand why.

Has anyone had successfully set SF=12 in the US band?

[conradholt]

I'm guessing only DR0-DR4 are implemented for the mkr. Is there any way to enable SF12 or DR8 on the mkr for the us band?