Originally Posted by
lsquare
My understanding is that those flights can't have SDFC.
Correct. Which is why I called it out separately but LHR-SFO doesn't qualify and has plenty of connections if the non-stops aren't available (fare routing rules aside).
For outstations with once-a-day flights (e.g. South America to IAH or Asia to SFO, etc.), if your ticket originated in the US then you can just change your flight using the flight change button and move up (or back) 24 hours which is similar to SDC. Both require the same fare class to be available for a free change.
-RM