This is looks like totally wrong approach. Configurations like this should be stored in the config file and kivy has nice interface to work with config files. All the config settings are loaded in the memory and you should work with these. If user changes configuretaion - you save to the config file, in order to be available for next time when user starts the program, but still you work with config settings that are loaded (as been changed in the meantime, i.e. in memory is always copy of the config settings as in teh file).
Even if there was no interface for config files in kivy, this should be a variable (most probably app attribute) that you work with, instead of reloading py module.
Even if there was no interface for config files in kivy, this should be a variable (most probably app attribute) that you work with, instead of reloading py module.