Externalized frame loses focus

If I have two windows stacked and I trigger the externalize action (button or hotkey), then the window that had focus, loses the focus. Focus is given to the non-floating window below. I think this is a bug, but if not is there a workaround to keep the current window focused?

thanks!

Not exactly bug, more missing feature. I’ll put it on the todo-list, should not be that hard to implement.