Seeing as it's a wrapper around S::WE, I'd be very surprised if it could do something that S::WE couldn't do. However, it can help redefine the problemspace in a different way. But, that's not your issue here.

Now, if you wanted to do a conditional within the formula, there isn't a Perl module that will help ... right now. Maybe this is a space for you to write one? Have a way to help generate the string that can be passed to S::WE based on some templating?