To my knowledge, NLD uses the routines of jezzab/DUMLdore to upgrade the firmware. Since jezzab/DUMLdore does not support an upgrade from 5.100, there will be no news about this.
Definitely dead. I managed to roll back from .510 to .100. Sent messages to NLD offering my script to achieve this. That was 2 months ago with no response.
Lies by this guy. No one can downgrade from .0510 firmware currently.