I think this suggestion could be handy. I use it in xplorer², which gives you the option of setting the default as being either the whole filename+extension, or just the filename for renaming. Maybe the same option could be built into SSC too? That way, people could be free to choose whichever they might prefer. This could be preferable to (say) fixing it as either one or the other.
It can certainly be time-saving and mistake-avoiding to be able to fiddle with this default setting to suit your peculiar changing/needs of the moment. It's one of those little things that matter.