Chord Tracks?

I'm just getting in to the deeper functions of os2xl.I peeped out the chord tracks to use them in my productions.I came from a Roland Fantom x, so I'm a little use to them.How many of you use them on the regular? I made one of my own based on a chord chart. It worked out , sounded good but I only assigned 4 keys,it triggered 5.someone school me on this.

i have never used this function, therefore i also urge someone to help this guy so i too can learn