I've setup VSCode to use CTRL
+ CMD
+ ↓
to duplicate a line downwards like I had setup for Sublime Text 3. This causes a "beep" in macOS due to issues with Electron.
To fix:
mkdir ~/Library/KeyBindings
vim ~/Library/KeyBindings/DefaultKeyBinding.dict
{
"^@\UF701" = "noop:";
"^@\UF702" = "noop:";
"^@\UF703" = "noop:";
}