usermin with caldav and cardav functionality

I am using usermin a lot. it has a better search function than thunderbird, and it has a beautiful user interface. I want to push this out to my clients! However I am a big user of caldav and cardav, and I push my clients to do the same so I can back them up and help them technically.

If the folks at virtual would implement caldav and cardav for usermin so we can connect to a server this would compliment this app and truly bring it to the next level in my perspective.

Are there any discussions on this or even implementation I haven't seen?

Thanks, Guy