In this new joint paper by our Prof. Kathleen Ahrens "Comprehension of metaphorical expressions varies with novelty", published in the Journal of Psycholinguistic Research under Springer Nature, the research team found that novel metaphors decrease the interpretability and acceptability of sentences compared to conventional metaphors and literal sentences. Metaphor signals have minimal impact, except for double signals, which increase acceptability for novel metaphors but decrease it for conventional metaphors.
Open access to the article from HERE.