After a few weeks of personal testing and others trying the new LPC and keyboard firmware combo, I want to recommend everyone to upgrade to it as per:
The only requirements are another computer (preferably with Linux), a screwdriver and a MicroUSB cable.
The updates will greatly reduce the battery drain in “Off” mode by making use of deep sleep modes on both the keyboard and the LPC controller. We don’t know the exact amount of power draw that is still there because we don’t have the tools to measure such low amounts of current yet.
All post-crowdfunding MNT Reforms already ship with this update.