I may be wrong but it seems to me that it wouldn’t matter where on the flow perimeter the injector squirts from.
My comment wasn’t clear. If you were to look at a round runner head on I don’t think it would matter what degree of the circle the injector fires from.The bump might be there to add turbulence near the injector to improve air/fuel mixing or to push the airflow towards the offset injector to improve air/fuel mixing.
The injector offset may be to better aim the spray of fuel in the direction that the air flows through head. The ports in the head aren't a straight shot to the valve/cylinder, they each bend right or left towards the valve.