This is a feature the Unreal Tournament games had where holding the crouch button would prevent your avatar from walking off edges -- VERY handy in a game like DRG. You can even relabel it the 'care' button.
Secondly -- and as a bonus -- an actual crouch could add some gameplay depth while hastily fleeing from bugs being able to travers under structures that might be too tall otherwise and too dense to stop and pickaxe while in a rush.
There is a reason every FPS game has a crouch button.
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