join rotation problems

Seeking to rotate:
- Hash Join { s }
-   NestedLoop Join
-     LDFTriple { ?a, <http://example.org/m/b>, <http://example.org/m/c> }
-     Hash Join { s }
-       Hash Join { s }
-         Table (?s)
-           {s=<http://example.org/foo>}
-           {s=<http://example.org/bar>}
-         Table (?s, ?o)
-           {o=<http://example.org/bar>, s=<http://example.org/foo>}
-           {o=<http://example.org/baz>, s=<http://example.com/foo>}
-           {o=<http://example.org/foobar>, s=<http://example.com/foo>}
-       SPARQLBGP
-         Quad { ?s, <http://example.org/m/q>, ?.blank-0, <http://test.invalid/graph> }
-   SPARQLBGP
-     Quad { ?s, <http://example.org/m/q>, <http://example.org/m/a>, <http://test.invalid/graph> }

Disallowing rotation, just 1 quad.
Seeking to rotate:
- Hash Join { s }
-   SPARQLBGP
-     Quad { ?s, <http://example.org/m/q>, <http://example.org/m/a>, <http://test.invalid/graph> }
-   NestedLoop Join
-     LDFTriple { ?a, <http://example.org/m/b>, <http://example.org/m/c> }
-     Hash Join { s }
-       Hash Join { s }
-         Table (?s)
-           {s=<http://example.org/foo>}
-           {s=<http://example.org/bar>}
-         Table (?s, ?o)
-           {o=<http://example.org/bar>, s=<http://example.org/foo>}
-           {o=<http://example.org/baz>, s=<http://example.com/foo>}
-           {o=<http://example.org/foobar>, s=<http://example.com/foo>}
-       SPARQLBGP
-         Quad { ?s, <http://example.org/m/q>, ?.blank-0, <http://test.invalid/graph> }

Disallowing rotation, just 1 quad.
Seeking to rotate:
- NestedLoop Join
-   NestedLoop Join
-     LDFTriple { ?a, <http://example.org/m/b>, <http://example.org/m/c> }
-     Hash Join { s }
-       Hash Join { s }
-         Table (?s)
-           {s=<http://example.org/foo>}
-           {s=<http://example.org/bar>}
-         Table (?s, ?o)
-           {o=<http://example.org/bar>, s=<http://example.org/foo>}
-           {o=<http://example.org/baz>, s=<http://example.com/foo>}
-           {o=<http://example.org/foobar>, s=<http://example.com/foo>}
-       SPARQLBGP
-         Quad { ?s, <http://example.org/m/q>, ?.blank-0, <http://test.invalid/graph> }
-   SPARQLBGP
-     Quad { ?s, <http://example.org/m/q>, <http://example.org/m/a>, <http://test.invalid/graph> }

Disallowing rotation, just 1 quad.
Seeking to rotate:
- NestedLoop Join
-   SPARQLBGP
-     Quad { ?s, <http://example.org/m/q>, <http://example.org/m/a>, <http://test.invalid/graph> }
-   NestedLoop Join
-     LDFTriple { ?a, <http://example.org/m/b>, <http://example.org/m/c> }
-     Hash Join { s }
-       Hash Join { s }
-         Table (?s)
-           {s=<http://example.org/foo>}
-           {s=<http://example.org/bar>}
-         Table (?s, ?o)
-           {o=<http://example.org/bar>, s=<http://example.org/foo>}
-           {o=<http://example.org/baz>, s=<http://example.com/foo>}
-           {o=<http://example.org/foobar>, s=<http://example.com/foo>}
-       SPARQLBGP
-         Quad { ?s, <http://example.org/m/q>, ?.blank-0, <http://test.invalid/graph> }