To be clear:
1) <report_results_immediately>0|1</report_results_immediately>: It is placed in the
cc_config.xml file. cc_config.xml goes in the BOINC folder, and applies to all projects.
2)
app_config.xml did not replace
app_info.xml (aka anonymous platform). app_config.xml is a simpler way to do some of the things app_info.xml can do, and can be used as an alternative to app_info.xml. At least one project (WCG) will not allow anonymous platform, so app_config.xml was developed as an alternative method to adjust scheduling parameters. app_config.xml requires later versions of 7.0.xx, but I don't recall exactly which one is started with. Both files are project-specific, and must be placed in a project folder under BOINC. I do not believe that you can use both at the same time for a particular project, but I haven't tested that.