It can be a significant feature for seeking after minimized sidebar space by only showing one column instead of two, while keeping enough view height for both notebooks and notes.
Building an unofficial plugin may be helpful, but it needs sufficient API supports of panel components, including all relevant APIs for the right-click menu.
I will check it out and try to sketch a panel just as we expected, if possible.
But intuitively, this is indeed a fundamental requirement that should serve as a cornerstone.