ARC OVERRIDE

It's not new, it's been there all along.

See table 4 below the section this link will take you to:

linuxcnc.org/docs/devel/html/plasma/qtpl...html#plasma:main-tab

Arc Override is used to make fine adjustments of torch height as the consumables get consumed while not changing the set voltage on the settings page.
As the nozzle is used, the hole gets slightly bigger so needs to be a bit closer to material for clean cutting, usually needing lowering the cut volts by 2-5V.
I also often have to use it to raise the torch by 4-8V when the material is not exactly 3mm thick, here you order 3mm plates but sometines you get anything from 2.5-2.8, rarely