From the drawings of the panels in their manuals, it looks like the PSR-640/740 also had two buttons for intros ("Count Intro" and "Intro"), as well as two buttons for endings ("Simple Ending" and "Ending"). But I thought that the old two-variation SFF1 format also supported two intros and two endings, even if the keyboards didn't actually have separate buttons for them, so I'm not sure whether the PSR-630/730 supported two intros and two endings, or just one intro and one ending.