Thank you for your feedback and I apologize for the inconveniences you had!
This option is easily disableable, on the first show of this message everything you need is to just check "Do not show this message again" checkbox in the dialog:
Which is why it's supposed to be enabled by default.
Next we will consider your feedback regarding the blacklist for the following versions.
Finally the option mustn't prevent the system from going to sleep mode. It only reacts on Logoff\Restart\Shutdown. Can you double check that if you enable this option the program prevents the system from going to sleep mode? If it's so please send us the report from that notebook.
In order to send the report you should proceed to "Main menu -> Help -> Report a bug", and in the opened dialog enter your e-mail and a short description of the problem. This helps us to investigate the problem more detailed