I tend to quote ascent in AC parkruns when I'm trying to describe a race to someone for whom AC parkrun represents a pinnacle of steepness. But it only really makes sense for races c.5k.
I'll have a think - mud would be a good one but I'm not sure where I'd use. No scratch that, mud is measured in Doyntons:https://m.youtube.com/watch?v=0F60HWwdsRI
See from about 60s onwards...
If that is 1.0D though, most races are going to have to be in milliDoyntons.