vertex
plans contains only switch(plan) cases, assigning xerrAvatarSize (pixel width = ceil(height * .75), height <= 256), xerrAvatarAnchor (normalized), xerrAvatarAnchored, xerrAvatarY (positive upwards), xerrAvatarView (radians), xerrAvatarSpeed (amplitude multiplier), and xerrAvatarKnown = true. Plan IDs are 1..4095; the default branch never enables a portrait.