The choice menu's Flake Link called openFileLoadPicker, whose import was
dropped in #386; the ReferenceError was swallowed by the catch, so the
picker never opened and no link was added. Use pickFlakeTarget instead.
Choice links get per-choice grid overrides (variant_link_overrides), show
under a "<group>: <choice>" heading in the linked column, are listed in
Generation Data, and use the shared link override editor.