Edit: Looks like you can't delete posts here :)
I misunderstood how this works now I think. If you delete the "Start Page" tab then the window closes, if you delete all other tabs then it brings up the "Start Page" tab, which is probably a fine solution in general, though I do think having open pinned tabs should keep the window open regardless? I would be in support of waiting for users to manually close the window, but it isn't a necessary feature.
