Can you really space people out all that well at half capacity? People are packed in their like sardines anyways when the stadium is full. Let's just say the amount of space alloted to each "seat" on the bench is not reflective of the average fat American ass. We always bracket our 4 seats with seat backs to keep people from pushing us out of our seats. No way you can observe the current separation distance that is recommended at half capacity. You would probably need to do 1/4 capacity, and even that might not do it.
Whatever, I'm renewed and got my tickets and I'm not particularly worried about it. But from a personal perspective I don't feel any safer at half capacity than I would at full.