I just found out, that if I change the URLSegment of a Page or even change the hierarchy SilverStripe has some mechanism to map the old URL(s) to the new URL(s). As this is a feature I've never heard of I just wanted to ask how reliable that one is respectively where to get more info about it.
The reason why I'm asking is that I am in the process of restructuring our complete website. With approximately 2000 URL changes, correct redirection is a big issue. If SilverStripe can handle this that's fine with me. Otherwise I would have to develop such a feature by myself.