Essentially yes.

The CS records the midi data coming in from the part of the keyboard one is using to drive the arranger engine, and when the playback button is pressed it simply sends "BACK" to the arranger over a specified channel those notes.

So in effect the CS is now "playing the arranger" with those recorded midi notes, which then leaves the player free to play both hands without the need for one hand to be "tied" to generating chords...

Dennis