Temperature Compensated Crystal Oscillators (TCXOs) is what they should be looking for. And to be clear you can get SX1262 variants with such, eg: https://wiki.seeedstudio.com/wio_sx1262/
For the detailed run down, see https://cdn.sparkfun.com/assets/f/f/b/4/2/SX1262_AN-Recommen... page 14
> In the case of an SX1262 operating at +22 dBm in the US 902 – 928 MHz band, the frequency drift measured during the maximum LoRAWAN™ packet duration stays below the maximum limit, provided thermal insulation is implemented around the crystal during PCB design.
> At extreme temperatures (below -20 °C and above 70 °C), it is recommended to use a TCXO.
> For any other frequency bands corresponding to longer RF packet transmissions at +22 dBm, it is recommended to use a TCXO.
Theory and reality are different here.
As used in the meshtastic devices this chip does actually fail doing normal Lora transmission under reasonable conditions.
I know because I've seen the exact failure.
You've seen the failures in variants with a TCXO?