I don't think this restriction is limited by the BS5, just the BeoPlayer software. I have a colored list with more than 9 songs that I created on the BS5 itself - although my BeoPlayer settings are still set to 9.
I did create the list by dropping albums into the list, and there are probaby less than 9 albums, but when I look at the list on the BS5, it shows the songs, not the albums so there are definitely more than 9 items there.
Stan