Simple:
Currently the "Adjust" key works as a modifier for the movement keys, whatever those may be (WASD, cursor buttons).

But I would like to use "Adjust" + "Crouch / Stand up" and "Go prone / Stand Up" for the higher and lower adjusted stances, and "Adjust" + "Evasive left / right" for the sidestep. It should be possible to bind all four adjustments to a separate key / combination of keys.