Articulation placement (staccato, accent, etc.) relies on VexFlow's automatic stem-relative default and should be confirmed, not assumed, per shared-stave voice

Articulations are conventionally placed on the side of the notehead opposite the stem, so two voices sharing a stave with opposing stems naturally get their articulations on opposite sides without explicit authoring.

An articulation rendering on the wrong side (e.g. colliding with the opposite voice's notehead or beam) because VexFlow's automatic placement didn't account for the shared-stave context the way it accounts for single-voice stem direction.

Gould, Behind Bars, ch. on articulation placement — default positioning follows stem direction; Ross, The Art of Music Engraving, states the same as standard practice.

This rule is about where marks land on the page, so it can only be judged after engraving. Collision and spacing faults live here.