deck squat foot position

In performing the deck squat, I can keep my feet together in the elevated version but as when I take it to the ground my feet come apart. Sometimes only a little bit other times they widen closer to hip width. Being a diligent student, I add some elevation, maybe 5cms and feet together again. Question one; it is correct to keep the feet together/very close? Question two what can I do to aid getting a proper deck squat from the floor? I am more diligent in spending time on my calves and achilles to aid this movement. Any insights appreciated. 

Hey Amanda, in this case for the squat I prefer the solution of holding a little weight in front of you with extended arms. The solution of something under the heels it is the last option.

So hold a small weight for the entire squat? Doing deck squats today and all it took was a few cms (to roll back on) too keep feet together. Oh so close.

Yes, if it is enough to fix the deficit on the ankle then it is ok.meanwhile work in order to restore the ankle mobility.

Added weight keeps feet together. 

DoI stay on step one or progress up following the sets and reps with added weight, Then restart at step one without weight?

You can progress on the following sets and reps. 

it is not possible for me to say how much time do you need to restore the ankle mobility.