Theme settings store __active_tab of vertical tabs.

The theme settings are storing superfluous settings related to the active tab when using vertical tabs.

'theme_my_theme_setttings' = array(
  // ...
  'global__active_tab' => 'edit-theme-settings',
  'bootstrap__active_tab' => 'edit-javascript',
  // ...

This causes features exports of the settings to change when you view the page, use another tab, but don't make any real changes. The result is if you are using features, the feature will show as overridden because of this bug. My guess is that the theme settings save function is blindly adding settings that don't actually make sense?