Not sure if this is a feature request or a bug. Depends on your intentions, I guess. But in any case:
On Windows 10, trying to add my default User download folder to the monitored folders list without monitoring its subdirectories. There is no way to do so. You have to select a terminal node in the directory tree:
Of course I can make a dummy folder for a workaround, but it should be possible to select a non-terminal node for monitoring. OneDrive does it like this:
I'm using MusicBee 3.3.7367.38620, Windows 10 Home
Thanks,
Jim