I’ve only really had gravel rash on the outsides of my calves and thighs – probably because you often go don clipped in so you can’t move your legs.
I know from my own experience, shaved leg gravel rash tends to heal in a few days, hairy leg gravel rash takes longer, goes manky and itches like hell.
Just my own experience, you’ll probably be able to dissect, over-analyse, and tell me I imagined the whole thing. 🙄