The VS solutions I often work with consist of a single executable project (console app, web app) and many class library projects that are all r
Generally there is only one configuration file and thats the configuration file of the executeable (.exe.config, web.config).
Any assembly redirects have to be placed in the configuration file of the executable.
Configuration files of dlls need to be loaded manually using the ConfigurationManager class. See also this question Equivalent to 'app.config' for a library (DLL)