Providing intelligent feedback to aid authoring has been proposed as a way to speed up authoring, give the author more control, and to enable the authoring of more complex interactive narratives. However, there is little research investigating what concrete feedback items would be useful for interactive digital narrative (IDN) creators. In this paper, we discuss potentially useful feedback items in relation to authoring goals and concerns. We perform a systematic literature review to make a list of concrete feedback items of interest related to the most emphasised concern of authoring -the effect of the interactive narrative on the user. We identify 47 User Experience (UX) dimensions in the IDN literature that could serve as useful feedback items, covering 8 categories -Agency, Cognition, Immersion, Affect, Drama, Rewards, Motivation and Dissonance. This list combines and untangles how different IDN researchers have interpreted and expressed interest in the complex idea of UX in the past decade and gives us insight into what concrete aspects of UX might be useful to estimate via automated feedback.