Am booked as companion in F on AMEX companion ticket. Couldn't find on DL website an answer to the Question: if using the AMEX Companion Certificate with both the primary rider and companion booked F, can they SDC to a different flight in F (24 hours or less before departure) assuming F seats are available?

I know those booked in F can make a change but just making sure the companion on a companion tic booked in F can do the same.

Thanks for your help!