My build system outputs different executables depending if i'm on Mac or Windows so:-
The questions is how can I set these depending on the platform, I have tried wrapping platform checks such as the following but it doesnt seem to work?
I think you can have platform user settings file overriding user one.
Maybe try overriding these settings for Mac in /User/Preferences (OSX).sublime-settings ?
If that won't work then another suggestion is to put these setting in the project file. This will work because I'm using it like this.