Indeed an option where we can mark the files & folders we would like to move to the back of the disk/partion would be very welcome, just collectively using file size & type to say Defraggler what we would like is simply not enough.
VERY GOOD TOOL
Some ideas:
-Queue for defragging sequentially(especially useful when you have a lot partitions
-Option for "Always analyze before defrag"(Just to make sure nothings gets damaged)