Functionality to open a tab for privat browsing within a normal window. For when you just need to do something in private mode, but don't won't to open a new window.
This idea is great, but i think the private tabs must have a corner dedicated to them, otherwise it would be easy to accidentally use a normal tab when you meant to use the private one.
But i'm sure there's hundreds of better ways to circumvent that issue.
I really like this idea. At first I thought it may be impossible to embody it because of some engine limitations, but then I found Waterfox, where this feature is on by default. I still prefer to have it in Firefox though.
UPD: Now I think Waterfox do it through containers, so I can't say if this is the same as private tabs.
Why have we not added the incognito tab to Firebox? We protect spam advertisements while using many social apps because of our search engines. Customers can gain more trust by using Incognito mode to research what they want in the Firebox browser.