We're just at the very beginning of building this, so specific styles aren't finalized yet. We are also talking with as many designers as possible to make sure it's themeable in the way they want. At the end of the day, we won't define how it looks, but rather enable you to be as creative as you want to be.
No matter if the angle is configurable or not, the current default is a bug rather than a question of taste. The lighting angle is one of the few design choices where there is a clear right and wrong on iOS.
