@imedia You don't need to change fuse for OTA. It's mostly for low battery.
I've use mysensors boot loader from MYSController 0_1_2_282.
However you need usbasp bootloader burning cable and also I use avrdudess s/w to burn boot loader.
I don't know why but I was unable to burn bootloader from arduino or any other s/w.
Only problem is after you use mysensors bootloader, you can't use arduino to burn firmware on it.
Ah I use arduino pro mini 3.3V version.

After you load firmware on MYController, you have to reset node to start burn firmware from controller.

Hope this save your time.

Thanks.

@jkandasa You are right. It's working now after clear cache. There is no plan to firmware upgrade at this moment. I will let you know when I do test this function.

@jkandasa Thanks. Finally I've solved the issue but not in MyController.
You are right. I did map new firmware and push reset button then it works however MYSController behavior is a little bit different for battery powered node.

When I look into smartsleep(), it send heartbeat() before going to sleep.
I guess MYSController check firmware version between MYSController and node then if it's different, it send reboot command automatically. Then node restart and process firmware upgrade. So firmware upgrade works well with battery powered node.
If you add this function to MyController, it will be great.

Thanks.

I can confirm smartsleep works fine with mysensors 2.0.0 (battery powered arduino pro mini 3.3V )
Thank you for your support! This is awesome controller!