@Boldline VS font manager can only link to the fonts.
If you have some folder(s) with fonts, that are not installed, then in the font manager just use "Add Folder". This creates a font "group" that points to the content of the folder (and its sub folders).
Adding / removing font files from the folder will automatically update the "font group" (it is a sort of "virtual" group linked to the folder content).
It is always a good idea to have large collections of fonts organized in folders (and not add these to the OS).
In VS these groups can also be accessed separately (improving the font scrolling time) by selecting the font group, or merged "virtually" by selecting the "All Fonts" group (clicking on the button next to the font name search field).
Here is how I have for testing, "color", "variable" etc fonts in separate folders (even testing "windows" fonts on mac).