Hi knives,
After checking this topic, I've removed limit all together.

I’ve also added an easier way to open bookmarks in private mode.
When the radial menu is enabled for bookmarks, you can use the middle mouse button to open a bookmark in a private tab: middle-click → Open → Open in Private Window.
I plan to add more functionalities to this extension, it would be great to hear your perspective - what could be improved, added and so on. Feel free to further edit your comment and add more info or write to me over github

Thanks for trying the extension and for the honest, helpful review. It helps me improve it