ZIP is fine, I didn't bother to make a Github repo for k3flasher yet. I will if others jump aboard and start developing with it.
The error being shown seems to indicate that the device does not switch into RAM kernel mode. I would give it one or more tries to see if it never sees the RAM kernel, but I guess it's just another case of dead battery or hardware failure (i.e. the "endless reboot" situation). Host side / software-wise everything should be OK, I think.