I prefer use "New Private Window" function when I use Opera. But, its need I manual activate and close normal window. My suggest is create a function which in "Preferences..." item to setup default activate Opera browser in Normal or Private window?
You can choose in which mode you want to open Opera by right clicking on Opera, after that you'll see you can choose from tasks:
- New tab
- New Window
- New private window
Nice day, Brtnik.