Do I need to care about any more configurations when using it along with proguard? Like extra lines in proguard.txt or change of mapping files when uploading to my crash reporting tools?
You shouldn't need to change your proguard config to use redex. For mapping files, the one thing that can trip people up is that we strip out source file names. After you run redex there should be a /tmp/filename_mappings.txt to do the back-mapping, similar to proguard.
If you're using third-party crash reporting tools that don't understand that back-map, though, you can always turn off the source stripping. We describe how to do that here: https://github.com/facebook/redex/blob/master/docs/Config.md.