I use a very OS specific shortcut by working on the tables which are text files: Ver 7 to 8 file libraries copy - #3 by retiredfeline
In the past I have suggested that the user entries be kept separate from the system ones but then you couldn’t be assured that the user ones will be on top without some editing. But perhaps reworking the list displayed could work. It could look like this:
--- User ---
user lib1
user lib2
...
--- System ---
Audio_Modules
...