I have installed the OpenGL ES 1.1 and 2.0 of the PowerVR SDK from the Android SDK Manager. Where should I point the IMG_SDK_HOME in order to build samples from both?
Short answer: Point every project to SDK you are building the sample from (you can override the environment variable on every project).
If you don’t want to bother to change that variable every time you change the API there is the option of copying the /build, /tools and /shell from one SDK to the other and point to the combined directory (plenty of files will be overwritten but there is no problem because those are the same). This will work because we designed our SDK to be crossplatform.