SC periods are a mess simply because the repercussions aren't there like they are in real life. In LFS, you bin it under SC, and generally at worst, you limp to the pits and get a "fresh" car or at best, can carry on as if nothing happened. In rare cases, you get flipped and end up DNFing. In real life, it can mean a premature end to your race, a cost to you or the team, and possible revocation of your license.
The big issue as I've seen it is the racers still thinking that an SC period is still the race, and driving as such, either full on throttle or full off. The most massive problems under SC are when drivers do the accelerate forward and mash the brake tyre warming. That is, from my experience, the worst cause of accordian effects under SC. Weaving tends not to mess the field up as much, as long as people keep their speeds in check and know how to control the car and react to it. That's the big problem, as I see it. Drivers not completely paying attention to their surroundings, and worrying more about how much heat is in their tyres or whatnot.
The key is to be gentle under SC. If you get hit from behind, assuming you didn't do any untowards actions like brake-checking, it would tend to be the following cars fault. Do everything you can to not hit the car ahead, and if everyone follows that, there should be a decent reduction in incidents.
And yeah, some of that tyre warming weaving was just...wow. I don't see how some of you kept it on track during it.
d