The use of Flows is one of the greatest features, for me. I produce a lot of works with multiple movements -- 'Et in terra pax' etc. Instrumental parts are created almost entirely automatically, with title headings for each flow, and "Tacet" if the instrument is not used.
Another under-appreciated feature is to Change the Note Spacing at any point in the score. So bars in 2/2 and 3/8 can be spaced differently. It's also a great way to 'fill' a set number of pages.
My post about creating SMuFL fonts is here: viewtopic.php?f=4&p=8007#p8007