Requiring two characters to mark the end of a line introduces unnecessary complexity and ambiguity as to how to interpret each character when encountered by itself.
ɹᵻkwˈaɪɚɹɪŋ tˈuː kˈæɹɪktɚz tə mˈɑːɹk ðɪ ˈɛnd əvə lˈaɪn ˌɪntɹədˈuːsᵻz ʌnnˈɛsᵻsɚɹi kəmplˈɛksᵻɾi ænd ˌæmbɪɡjˈuːɪɾi æz tə hˌaʊ tʊ ɪntˈɜːpɹɪt ˈiːtʃ kˈæɹɪktɚ wɛn ɛŋkˈaʊntɚd baɪ ɪtsˈɛlf.