Below an amend-example for my last comment (as remainder for me)...
<code><pre>
% test {yieldto c2} {out "** c2 .. back to c1"; yieldto c1}
  ++ test enter
    ++ c1 enter
      ++ c2 enter
    ** c1
      ** c2
      ** c2 .. back to c1
    -- c1 leave
  ** test
  -- test leave
%
% namespace which -command c2
::c2
% c2
      -- c2 leave
%
</pre></code>