I think the whole "Awuzie at S" thing is for depth and strategery. It's always a banger if you have the CB depth, and you can save that roster spot for another young player, because he can play S if Woods goes down.
Assuming the rooks don't officially start, you have Woods go down, Awuzie can go in at S and Diggs can roll in.
You can also play some 3 safety formations against some teams if you think it might confuse them and/or do some things on defense that helps you stop 'em. Woods showed pretty good slot cover ability, a package with a 3rd safety on the field that can tackle and cover could let you disguise coverage and responsibilities. Disguising helps get 'dem there turnovers.
You also just might want to play some Dimes coverage with 3 safeties on top facing the line of scrimmage, decide to blitz with the LB with press coverage, etc. Doesn't have to be purely passing downs, 2nd and 7-8, if their OL isn't that great and you've been doing a good job against the run, you could have situations with Dime coverage, 3 safeties, and your LB playing the run while one of Woods or Awuzie drops down, either/or is kinda the point.
I don't think the intention,at all, is to challenge Woods for an immediate starter spot. In my opinion,it's depth and situations where you think you can get your best players on the field with the benefit of being able to do multiple things while having some element of surprise + cover ability.