I also have 6K songs, but with 6th and 7th gen Ipod. I have a 2012 LS 460L, with Mark Levinson sound. I am not sure if my problem is related to indexing or it is just a crippled user interface. My problem is that there is no reasonable way to find a song out of 6K songs.
Before I bought this LS, I observed that Infinity and Hyundai Equus sound systems have a reasonable scrolling capability like the Ipod itself. That is, if you spin the folder selector fast, it jumps to a fast mode, and the first letter of the song title group is displayed.
With the LS, there is no such feature. It takes forever just to scroll through a few hundred songs. Then once you find a song in a list, if you jump back between the text and list, you lose your place in the list and have to start over! I am going back to the dealership and complain. I am hoping there is a firmware update.
