Build Configurations and Exclude from Build in Eclipse

Yes, I am using 9.1 Build 222.

Playing around with it a little more has revealed that if I have a single build configuration and I choose a file for Exclude From Build, it updates immediately and all is well. However, when you have multiple build configurations, you can choose which files you want to exclude from which configs--say I want main_test.c for the Test build and main.c for the Operational build. So when I choose my active build, I would expect the file listing to automatically update and exclude the right files, and also update the makefile. Frustratingly, when I choose my active build, nothing happens.