Thank you for contacting us and for your question.
RadInfiniteListBox was the first control we implemented and it was meant to be the base for our Date/Time pickers. Its performance however was very slow and that is why we replaced it with our completely custom implementation - RadLoopingList, which performs times faster and does the same job. Indeed, it seems that the help topic is copied when we converted the documentation to the new control. We will update this as soon as possible.
Otherwise the looping list is based on rather different approach and implementation than the standard ItemsControl and that is why it behaves in a different way in Blend. We will research the issue and see whether we can improve the experience.
I would like to thank you for your feedback and for bringing our attention to these issues - I have updated your Telerik points for your time.
Do not hesitate to write us back should you have any question/problem with our tools.
the Telerik team
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