How do non-mammalian synapsids compare in prominence to non-dinosaurian sauropsids? i.e. Pseudosuchians, Marine reptiles, rhynchosaurs, Eureptiles/Parareptiles, etc.

By prominence, I mean the amount of research currently being done or public consciousness.

no-one currently on the site has the expertise to answer your question. that said it is an abstruse area and to be frank most people/public neither know nor care!