Does English allow alveolar flap [ɾ] at the ends of syllables? If yes, how to syllabify?

In his Syllable Structure: The Limits of Variation, San Duanmu argues that the [ɾ] has to be syllabified as the coda of the preceding syllable because word-final [t] can flap as in sit in, but word-initial [t] can't. So you can't say time with a [ɾ] in 'a time when ...'. Another example he gives is mighty; he says that ‘the [t] in mighty is flapped, and so the syllabification must be [maiɾ.i] ...’.

Another similar example is [maɪɾˈaɪ]: it can only be interpreted as might I, not my tie because word-initial [t] can't flap.

In the book, he also explains the ambisyllabicity principle on page 60. He represents ambisyllabic consonants by underlining them (e.g. potato):