Thinking I should do the same with my internal flight to position me at LAX rather than SFO. At least it appears they've been giving pax booked on a reward the option to change to LAX and opening up space.
Only hiccup in my case is that I'll be originating in a very small city where there's only one game in town, so booking the contingency to LAX would result in a duplicate booking on the first sector, and Delta's system doesn't like those.
Time to make a gamble. 
