Hi @DmitriyKolokolnikov - I know it's been quite some time since your original post, but I wanted to update here in case you or others reading this post - in the new 300.1 release of ArcGIS Maps for Native Apps you can now use the `InteractionPreviewChanged` event to get updates about the state of the geometry while a user is making changes - for example during the drag operation when moving a vertex, or while rotating, moving or scaling a geometry or part. You can read more about this and other new functionality in the release blog. Please do post back if you've got any feedback about the new event.
