Just what I needed.

The extension does not work. It works if normal Firefox windows are open, but not if Firefox is already closed beforehand. Also, across my two laptops, the extension has a different icon which is really strange.

Works when you try to open a private window when firefox is already open, but It doesn't if you open firefox as private for the first time

Doesn't disable anything.

It works, just enable it in Private Browsing.

Not working on a new Laptop. I synced firefox on a new laptop and it's not working there somehow
Edint: My bad, you have to allow it to work on private mode, duh

I thought it wasn't working because other methods remove the option for a private window - it isn't even there. This one closes the window as it opens. So it sort of taunts the user... which is amazing.

it works

Does what it says. It does not allow for private windows to launch in Firefox.