Hide code for an hour after submission
The competition needs to strike a better balance between tweaking and algorithmic improvements. To encourage more of the latter, code for each submission could be hidden (during daylight) for an hour (or more) after submission. This would help on the Big Sunday Push. It would also mean that you could start testing new approaches an hour before a deadline without fear of being "tweak-bumped" (beaten by a tiny last minute tweak of your own code).