Hi - sorry if this isn’t the right place for this question but I couldn’t find another thread.

if we book using amex companion certificate and for whatever reason one of the parties doesn’t make the return but has to book a new trip to another destination, does that cause any problem? Not planning this but plans can change, especially these days. Looking at using the F certificate if that matters. And does it matter if the primary traveler or companion has to miss flight due to travel changes to another delta flight? Thanks