You must have Admin Level - Webmaster access to use converted times for relay entries.
When the course order is Y, L, or S to convert all best times to SCY, LCM, or SCM, respectively, you must also check Allow Course Conversion for Relays to do the same for relay entry times.
Click Events & Competition > Team Events from the left navigation menu.
Click Edit Commitment.
Click Edit in the Event Declaration Setting.
Check the Allow Course Conversion for Relays checkbox.
Click Save Changes.
When you pick relay athletes, it will use converted times from other course types if those are the best. The converted entry time is shown with the apostrophe after the best times of the first and third athletes.
NOTE: This has nothing to do with using relay lead-off times in individual events; those are based on the course order setting.