Yes, without even reading the rest: like aeh, I didn't parent such a child-- as in, my DD really was one that could be left for long periods on only-sort-of-supervion status, but then again, she was never impulsive or risk-taking this way--
but boy, howdy, was I ever one of these kids. I can remember being thrilled to hear about Parkour, because this was something that I'd basically been doing since I could walk... and I mean that quite literally. My mother took the mobile down over my crib and put the crib sides all the way down, when she walked in on me PULLING that mobile down (for the fifth or sixth time that week) by balancing on the top of the crib rail. I was about 11mo old. It got worse from there, frankly. I was fearless, wily, flexible, and impulsive.
I think back on some of the stunts I pulled as a pretty small child and I shudder at the risk, and wonder at what an overworked guardian angel I must have, frankly.
Yes, supervision with a capital S, now that you know.
Realize that your child lacks judgment that comes with lived experiences of consequences. Asynchrony may mean that some such children can readily envision possible negative consequences (like my DD seems to), but in other children (like me, and aeh, too, apparently)-- not-so-much.
My dad was another child like this-- he was EXHAUSTING to parent.
The asynchrony makes it so very tempting to ignore that basic personality quirk (risk-taking and impulsiveness) and how it interacts with high IQ and one's surroundings... but don't be fooled. Children are still very much children. They DO stuff that doesn't make sense, or that could reasonably be expected to turn out badly-- and they don't see those outcomes as even on the horizon.
