Default Domain w/Domain Mapping

I'll looking to have domain mapping (like the other WPMU Plugin available for download) plugin allow for redirects or aliasing, so I can choose a default domain if using more than one tld without having to add a 301 redirect.

So if I add, and, I'd like to be able to set my default domain to and have forward to (or even my original subdomain). My question is is this available via a configuration setting to allow multisite users to choose their default domain, or should I revert back to the non wpmu-domain mapping? How is this handled if I'm using the Pro Sites plugin?