I have already done this. The file saving process was still a really complicated view.
I have found that there are two types of Quick Access and they do not control each other. There is the Quick Access in File Explorer view which is changeable. Then there is Quick Access in the file saving view when you are in Microsoft Office products -this is not changeable and it appears the two are not related.
So my file explorer view Quick Access has been changed to be more simple for the children. Yay
To get around Quick Access in file saving, you need to separately go into excel, word and Powerpoint and transfer over the 'Save As' icon onto the ribbon (under Options/Save in the File menu). Clicking this icon or using F12 reverts the File Save As view back to classic and Quick Access does not get shown.
Microsoft bloat. Calling two different functions the same thing is really confusing. In addition, in the process of file saving, this Quick Access shows Teams folders which you cannot save directly to anyway! Stupid!
No wonder teaching good file saving techniques into folders is so tricky at Primary School level. It has taken me hours to figure this out.