• You control when USB / external drives are scanned. The "Install from USB
  / external drive" section has a new "Automatically scan when this tab
  opens" checkbox. Leave it on (the default) and it works as before; turn it
  off and nothing is scanned until you click Scan — handy when no drive is
  plugged in, or to skip the check each time you open the tab. The Scan button
  is always there for an on-demand look.