I think I requested elsewhere that public _tkinter/tkinter names be documented.  What you wrote already seems clear enough.

"Default mode is still wantobjects=1," The patch appears to change it to 2 in tkinter/__init__.py.

"/* Create argument list (argv1, ..., argvN) */
 if (!(arg ..."

/arg/args/ is definitely less confusing. Add /list/tuple/ to old and new functions.

One thing slightly puzzles me: the current PythonCmd is used in a call to Tcl_CreateCommand.  (Since the latter is not in _tkinter, I presume it is 'imported' in one of the includes.)  The new PythonObjCmd is passed to Tcl_CreateObjCommand. Does that already exist, just waiting for us to add PythonObjCmd?


I near as I can tell, the only differences between PythonCmd and PythonOjbCmd are /argv/objv/ and the following.
  
      PyObject *s = unicodeFromTclString(argv[i + 1]);
      PyObject *s = FromObj(data->self, objv[i + 1]);

I think I would make the name substitution either in both or neither.  It would be nice to reuse the rest of the code.