Kid-mode simplifications — what may be relaxed vs. what must never be relaxed

Simplifications for a young/beginning learner are legitimate when they REDUCE VISUAL DENSITY without teaching a wrong fact: larger noteheads, fewer bars per system, omitting ornaments/fingering that aren't the lesson's point, treble-clef-only, avoiding cross-staff writing/divisi. Simplifications become illegitimate the moment they teach something that has to be UNLEARNED: an accidental that isn't needed (or a missing needed one), an octave transposition presented as the notated pitch, a wrong stem direction 'for tidiness,' or collapsing a chord to one note where the taught harmony depends on all chord tones being visible.

(a) LEGITIMATE: a kid-mode lesson omits a key signature and writes every accidental explicitly. (b) ILLEGITIMATE: a kid-mode lesson shows a melody an octave higher than it sounds 'to avoid ledger lines' with no 8va marking — teaches a wrong absolute-pitch reading.

General engraving-pedagogy principle synthesized from Gould/Read's emphasis that notation should never encode a falsehood 'for simplicity' — the specific application to a young/neurodivergent learner is a Gradus-local policy decision (CLAUDE.md 'Who this is for'), not itself drawn from the four engraving authorities, flagged as such.

This rule needs the notated content and the rendered result together — the score says what should happen, the page says whether it did.