Just wanted to mention that I think the Peak District National Park and National Trust appear to be tightening up their rules around applying for permissions for fell races. In addition to the £50 'registration fee' that I've had to pay in recent years, this year they have forwarded my application on to Natural England. This is because the Kinder Downfall race uses a very short section of path that crosses an SSSI area at the top of William Clough. This is a very well established long used popular path and they've not mentioned applying to Natural England in previous years as far as I am aware.
I've been the RO for last 3 years. Also NT told me that Natural England say it can take 4 months to process the application and they advised me in future to apply for permissions a year in advance. So I'm posting this to make other Peak District based ROs aware. Not sure how people are finding things in other areas.