In the example text, I think "hōt" and "joke" should be "hot" and "jōke" instead. Also, the vowel in "to" is different yet again, so maybe it needs its own glyph. ⊚?
trouble / about: the 'u' should be marked, at least for 'trouble' to make it silent (or probably in both cases but differently, not sure about other similar words). But then there's 'o' in lemonade which is different from 'o' in 'trouble'. Also 'oo' in 'loot' seems strange (should be ⊚⊚ with the recommendation above). Or am I misunderstanding something in the point of the markings? Anyway, it hurts my eyes.