I haven't heard about it, but would expect fewer entries, and a different mix of racers entering. Most 4th cats are chasing points - sad but true.
I am seeing crashes at all stages of the race - I think the main cause is that it takes a fair bit of racing to get the right habits, and be able to maintain concentration for the duration of the race. I suspect the main cause is lapse in concentration, combined with not having the right racing habits ingrained. An analogy would be the difference in insurance premiums for newly qualified drivers versus over 40s.
Having said that, I also think that talk of crashes at 4ths races is somewhat exaggerated. I have seen 3 or 4 in the last two seasons, and was involved in 1.