better chain check

src/viewer/helpers/preset.ts

@@ -259,7 +259,7 @@ export const RcsbPreset = TrajectoryHierarchyPresetProvider({
         if ((p.kind === 'feature' || p.kind === 'feature-density') && structure?.obj) {
             let loci = targetToLoci(p.target, structure!.obj.data);
             // if target is only defined by chain: then don't force first residue
-            const chainMode = p.target.label_asym_id && !p.target.auth_seq_id && !p.target.label_seq_id && !p.target.label_comp_id;
+            const chainMode = Object.keys(p.target).length === 1 && !!p.target.label_asym_id;
             // HELP-16678: check for rare case where ligand is not present in requested assembly
             if (loci.elements.length === 0 && !!p.assemblyId) {
                 // switch to Model (a.k.a. show coordinates independent of assembly)