I think this is not a good idea, because then you have different names for extension modules, which will be recognized by one configuration but not the other.  This configure option should not change the sonames.  If this option is to keep pathes like /usr/local/include/python3.2 (instead of /usr/local/include/python3.2mu) or /usr/local/lib/python3.2/config (instead of /usr/local/lib/python3.2mu/config), then fine with me. Although in this case we should make sure that these pathes are available in the sysconfig module.