If you know the urls and handlers you can declare routes by patterns in config files that can be dropped into the /Setup/Routes folder. There is a file there named mojoRoutes.config that has example syntax for declaring routes. You can add additional files to declare custom routes in that folder using the example syntax.
I don't have a way for you to add routes programmatically as in the syntax you posted. That is one of the integration issues of routing that they can only be added from application_start in global.asax so typically one would have to recompile in order to add routes.
The solution you found in mojoPortal routing is recent work I did to make it possible to add routes without recompiling by using config files to declare route patterns. Routes are not currently used yet in mojoPortal but I plan to try to use it when I make the new tagging/category system in order to have seo friendly urls for tags/category lists. I have tested it with experimental code in the /Bog/ViewCategory.aspx page but I commented it out there because I was only testing for proof of concept to make sure I could get it working.