so USUALLY, if you can be accommodated
Because this is a new concept to some on this forum, even though there is an agreement does not mean that there are rights to the jumpseat(s). It is always a privilege that is the Captains to give. And protocol is essential when exercising this privilege otherwise agreements can be put in question. It has happened to all airlines at some point.
Over the course of time SWA has always been the most generous to other airlines and has been the leader of how liberal the agreements have become in the airline industry.