I prefer the front foot to be pointed at the target although I'll accept a slight deviation to the throwing arm side of the target. If the front foot plants pointing too far to the throwing arm side, that can put stress on the front hip, knee, and ankle joints because the rest of the body will try to open up more than the foot as the hip sand shoulders try to square up to the target. You might also limit hip rotation and end up throwing with more arm.
So, to summarize, I see there being possible health issues as a result if the front foot plants too closed. Maybe you could tell your coach that you've heard about possible health consequences and explain what I said above. Then see what he thinks.