TYPO3 Core

In the All Configuration section of the Install Tool, all options of type boolean, which are disabled, show a value of 1, but the checkbox is unchecked.
It is not clear to the user whether a feature is now enabled or not.

An example is [BE][showRefreshLoginPopup].

The default value of this option is FALSE.
So if the LocalConfiguration.php does not modify this setting the Install Tool will look like this:

Obviously this view is not consistent. The checkbox is unchecked. So what will happen if I click the "write configuration" button?
Will it set value to 0 now?
(The answer is: it will do nothing!)

Checking the checkbox now and clicking the button then will write the value 1 to the LocalConfiguration.php and the Install Tool will look like this:

Which is correct now.

But unchecking the box now and writing the changes (value 0) will bring back the first image again.