I think you have all other possible shortcuts there so maybe switch settings button with the quarantine one like it used to be. The gui improved a lot, mostly the bottom part, so there is no point in doing changes so that you have changes.The majority of our customers is over 60. That being said, I agree. What would you like to see in its place or how do you think the settings button could be made more useful? Would adding shortcuts to specific sections do the trick?
Obviously, that is my personal opinion but you guys can think about usefulness of each component on the main gui.