More on Locking layouts

Add to this the fact that while Layout Options can be adjusted Layout by Layout, Engraving Options can’t. Sometimes one may want to adjust the height of dynamics or tempi markings, or the curvature of slurs, differently in a vocal and an orchestral score. That would be useful.
As for “locking down” carefully laid out work, what is needed would be a lock icon on each system and another on each frame and page. One click and it’s locked.