C/A: see the relevant page from Doc 8168 VOL II, linked above.
Indeed, the starting point of missed approach segment is well defined for ILS / 3D approaches: it is just not called MAPt at the design level. Within the scope of the thread, that acronym does not apply for ILS approaches,
The part from VOL I, quoted verbatim by BJJ, opposes the paragraphs right above it. Given the explanation in VOL II, I'd say the 6.1.5 is just worded on the sloppy side. See for yourself: