I’m thinking that you should be able to just be clumsy and trip over thin air and face-plant, causing a certain amount of damage to your head. or to be graceful and rarely trip or stumble.
It’s late and I’ve worked maaany hours this week, so hopefully this makes sense to other people, lol
We have a smattering of traits that already do these things.
Parkour Expert makes a lot of rough terrain as easy to traverse as normal terrain. Light step reduces odds of setting off traps and reduces volume from moving.
Conversely, Bad Knees increases movement cost of rough terrain. Clumsy increases movement noise and increases odds of setting off traps (and has a few other random annoying effects).
With respect to the Clumsy trait, I THINK the risk of injuring yourself while climbing on rumble is treated like a trap, so Clumsy might affect that.