После долгой переписки с Кубино добился только такого ответа:
Так что вилы.Hello Eckosis,
Apologies for the late reply, the college (developer) that was in charge of your case was on a leave for some time. He told me that we can't make the firmware OTA update fro your Smart Meter as there's no more the source files for the older firmware.
We can offer you to reprogram the Smart Meter to the newer version, the only disadvantage of this is that this can only be done with a special tool and it can't be done OTA. the update is free of charge the only thing that will be to pay is sending the device to us. Let me know if you want to proceed so that I can open a request for the update.
I hope I was able to help you, if you have any additional questions please don't hesitate to ask.
Кроме отправки к ним, есть ли у меня варианты?