Much of the discussion here seems to be about the database limits that are now 2000.
It sounds like many people may not be aware of how the folder icon works.
I am using a 64GB card with well over 10,000 songs on the clip sport.
Ignore the database.
Format your card inside the sport
Connect to computer
When the external card mounts create a music folder
Inside the Music folder add folders with artist names or whatever you want.
Add your songs - thats it
When you boot the clip select the “Folder” icon
Select “External” to browse the card - It works great.
Probably will work with 128 GB cards but I havent tried it.
In the settings select customise and turn off sdcard, music, and any others you don’t need. I just use Folder, Radio and Settings - very simple.
This may not be everyones ideal but it works well.