Ignore - had the settings under 'controller' and not keyboard...
Changing the option to 'hold' has no effect.
What I expected to happen: Holding the key should progress the meter when breaking veils in Kahl missions or healing the creatures in Duviri.
What happens: Nothing happens - the meter ticks down as if you weren't pressing a key. You still have to mash the key to progress.
How to reproduce: Set your 'Repeated Button Presses' option to 'hold' and do one of the above tasks.