Hyphens must fall at true syllable boundaries

Word underlay splits multi-syllable words only at linguistically correct syllable boundaries (dictionary/orthographic syllabification), never at arbitrary letter counts. Hyphens between syllables of one word are drawn centered in the gap between the two noteheads' lyric columns.

A lesson author writes 'beau-tif-ul' (wrong break — correct is 'beau-ti-ful') or splits a single-syllable word like 'through' into two lyric entries.

Gould; Read (consult a dictionary for correct syllabification).

This rule can be decided from pitches, durations and voices — no layout required. A validator can check it before anything is drawn.