The answer I spoke of you wouldn't like is to bring back the box, prescribe centering as the center of the box and add a 200 meter flight path rule. This would likely make some 40% er's obsolete.
Same basic idea I had in mind, however I don't think it makes anything obsolete. Most 35 - 40% stuff flies slower than Pattern models, and we're comfortable at 150 to 175m out in a 60 degree box. Anyway, it's a realistic solution, but it needs clear explanation to describe how to judge it when it comes to all cross box flying. Not my job, mon!