I have created two build configurations (settings copied from Release) to separate the free/premium feature set in my app via compiler constants. When selecting either of these new configurations, the Enable Proguard checkbox becomes greyed out/disabled. It is only enabled when selecting the original Release build configuration.
I have looked everywhere I know of for differences in the build configurations but cannot find any. What am I missing that needs to be changed so that Enable Proguard is not restricted just to the one original Release build configuration?
Update: I have attempted to compare build configurations in my .csproj file and this has failed to reveal the cause. Even copying the full and exact settings from the "Release" configuration to the "Release-Free" and "Release-Premium" configurations does not allow ProGuard to be enabled in VS. Adding the
Posting the comment on the question as an answer. Glad it was able to help you out but it definitely still sounds like a bug that might be good to report.
<EnableProguard>True</EnableProguard> to the build configuration, even though the box stays greyed out in the UI, try building the project and checking to see if Proguard actually does get run on the resulting APK.