With the new modifiable stance system, it's possible to not realise what stance you're in unless you view in 3rd person. Going from lowest crouch position down one step results in you sitting down, and unable to run. This is problematic in first-person as there is no oncreen indication of your current stance.
I suggest an onscreen stance indicator, perhaps something as simple as a small height-bar, with a colour indication to show ability to run. Ex. green - can run from this stance, yellow - cannot run from this stance.