Hello Markus, Arno,
Thank you for pointing out the need for such functionality. I have open a feature request in our Public Issue Tracking
system to turn on/off adding extra urls on page move.
Second request for feature to remove all the additional URLs is not available by design as it is very risky, because this potentially could brake a lot of frontend pages and could not be reverted.
When this is done through the API the developer is absolutely aware of the risk and could not do it by chance.
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items