sync command total size calculation

I use winSCP 4.04. In sync preview window it shows summary of uploading/reuploading/deleting files. It would be helpful to show total approx size of uploading/downloading. this would help to not transfer some data and so balance channel load.
I realise program wouldn't calculate sizes of directories, but sizes of files would be fine as well.
Thanks!

OK, added to TODO list.

This issue has been added to tracker.