Every button on the toolbar should be visible in the new RCE by default. The new RCE toolbar presently collapses if there is too little horizontal space to show all buttons. One must then click the triple dot (kabob) button every time they want to access collapsed buttons. Extra clicks are a pain point. Buttons that are out of sight are out of mind.
My first choice for implementing this idea would be to wrap toolbar button groups onto as many additional rows as are needed to show them all. A collapse button could appear at the end to satisfy those who favor a minimal look.
My second choice would be replacing the existing triple dot icon with an expand/collapse button so that one could expand the toolbar across multiple rows. The expanded or collapsed state should persist wherever one opens the RCE.