If a free function is "include()"ed that takes one or more arguments of an "exclude()"ed C++ class, a W1040 warning ("execution error W1040: The declaration is unexposed, but there are other declarations, which refer to it. This could cause "no to_python converter found" run time error. ...) is output.
Setting the "exclude()"ed C++ class' wrapper's "already_exposed" attribute to "True" is supposed to suppress that warning but it's not.
In the same script I have also "include()"ed C++ classes whose member functions also take one or more arguments of the same "exclude()"ed C++ class and the aforementioned "already_exposed=True" assignment is suppressing the W1040 warnings that were output because of them.
An interesting point is that the W1040 message contains eight (8) copies of the free function's signature as if its string was appended to multiple times.