Think I have put it back. The other things about leaving tools on the right are (1) that is where tool settings reappear, always docked however often one undocks and saves workspace, so even more screen space gets wasted (2) having the tool box below menu allows a fast lunge to top left for all tools that do not have a keyboard short-cut. I assume use of a smart mouse that flies like a hawk moved rapidly but with tortoise sureness moved slowly.(Kensington pocket mouse pro in my case)