Motorola Defy has the same hardware -almost- than my Nexus one: low internal memory, old and so on. Official version of Android is 2.3.3 for they.
Yesterday I have installed CyanogenMod. Now I have Android 4.2.2 on it. I have tested the API Demos at OS->Sensors->Rotation Vector. That uses OpenGL 1.0 or 1.1 , but not 2.0.
With old Android 2.3.3 it worked and now not => CyanogenMod is to be blamed. - or just missing the hardware requirements for this functionality.
I won't have issues when selling the app on Google Play?
Just check any app, which has 500,000 downloads or more! Some people doesn't read app descriptions, just want to tap a button and see an action. If they can't see an action in they point of view aren't they fault, because they taped on other app and that worked and don't care abut your description.
As how they don't care about your app and want action, you should don't care about they and accept they negative reviews. Those ppl are present in SO too: Here nicely asking a user a question and other want to see code, nothing else, just action, they don't care about text ( question).