What is and is not inherited from an earlier obstruction

The motivating obstruction concerns a particular combination of unswitched coordinates, switched scalar response, fixed free input, and gauge parameters extending outside the interaction plateau. Restriction of the gauge domain does not refute that obstruction.

For self-containment, no numbered result from another Landmark manuscript is required here. Section sec:defect derives the relevant first-order defect and a concrete large-support witness directly. Thus the restriction adopted below is compatible with the large-group obstruction referred to in the production plan as Landmark VI, Theorem 12, without requiring its unavailable statement as a premise.