Are you saying there needs to be a marked, mandatory corridor for some distance (100m?) before the actual start triangle, or something else?
Most events that I run in England have some type of short distance to the start kite, either marked with tapes or visible from the actual start block. I think something like 100 meters is ideal.
Definitely, need a marked corridor to start triangle, this is another way to get a competitor out of the view from following runners. Distance can vary - 20 to 30 sec running time shell be sufficient in my opinion
At the Flying Pig this year, we had a miscommunication about the start. The last call up line was supposed to be the trail crossing, and the triangle was supposed to be at the end of a mandatory corridor.
It turned out better than I expected, though. In the original idea, most people standing around waiting to start would not have seen people running the long leg, and they wouldn't have had a nice flat trail to warm up on.
I agree with you that a running start is best. In the future, though, when I'm faced with the choice between people seeing which way to go out of the start versus having a good place to warm up and having spectator opportunities, I think I'm going to favor giving away a little of the course.