I personally like the crouching as it is right now.
Having an actual crouch would look weird, in my opinion, since the blockhead body is entirely rigid (No bend around the torso, as it's a solid piece of plastic, with no bendable spine), it has no knees, and any moving the feet around would mean that the invisible legs would appear to be really long.
I don't think it would look right.
Also, think about people using peglegs. They are a full leg, yet have no knees, so they can't be adjusted in anyway beyond being fully-straight from the hips.
Plus, I'd hate having another button to use for crouching and then going prone.
I'm very comfortable with my keymap as it is.