"Hello, The headroom is needed since there are sounds that could distort otherwise. You will need to gain the levels in your DAW. It’s in 24-bit so you will not have any audible loss except a very minimal raise in the noise floor.
The boost setting affects the audio from the computer to the physical mains out of the unit. Not the audio from the unit to the computer. Boost is useful for raising the monitoring level when utilizing the device as an audio interface.
Regards,
Patrik - Elektron"