With new or reman m/c I would think that would not be a problem as from what I have seen the entire bore is nice and smooth. But, if a guy just took a m/c apart and didn't hone it or anything, then I could see where pressing it all the way to the floor during bleeding might put things out of their normal operating range when there is a full pedal...... BUT who, in their right mind, would rebuild a m/c and not hone it all out smooth?? I see your logic but but can't see it happening..... but I also learned a long time ago to never say never!!!