Really simplistically, I think as long as the air cleaner has access to the appropriate amount of air, and isn't located too far from it's original placement, then moving it in general would be fine.
My completely non-engineering based concern with how far you place the air cleaner from the engine is thinking air flow, currents, etc., reducing the amount of air available.
The thing I'm noticing about the OEM placement is the height of the air cleaner. I'm assuming this is to avoid as much crud kicked up from the road. More crud, less air, more frequent air cleaner changes, etc..
I'm wondering if you can determine the amount of air flow that the air cleaner needs to allow through and use a different shaped air filter that will allow you to keep the air filter intake where it is, but use a larger, flatter air filter. This way, you could greatly reduce the space taken up by the (assuming) cylindrical air filter chamber.
Just thinking outside of the box.