Ok let's see if I understand this:
With "Move systems files to the beginning of the disk" selected, each time you simply "Defrag", that operation will move the systems files to the beginning of the disk.
The right click (or via the toolbar) and "Defrag and Optimize (slower, use once a week)" only defrags and compacts free space. ? Does that particular selection's functionality remain the same regardless of whether or not "Move systems files to the beginning of the disk" is selected?
There seems to be 3 options of defragging: Simple defrag; defrag and compact free space ("Optimize"); and defrag but also with moving system files to the beginning of the HD.
Defrag: Defragments files only.
Defrag & Optimize:
"Move systems files to the beginning of the disk" de-selected - Defragments files & compacts free space.
"Move systems files to the beginning of the disk" selected - Defragments files, compacts free space, and moves certain files close to boot sector.