The users wants to cut n paste without chopping the beginning of the note off, this will allow that.
Reaper has non destructive editing, I haven't used S1 enough to know what it does but I assume it would be the same.
It is easy to script it up in Reaper to do what you want but S1 you are a bit more limited.
I did it in Reaper to allow the sustain to bleed into the next bar after cut n paste.