Have to disagree a bit. Octane is resistance to pre/ignition or auto detonation before spark due to heat, not burn speed once ignited.

Or/also ability to achieve smooth controlled combustion after spark event.

If you’re on the edge you can see this on a dyno with a stick car as it goes from a bit of a jagged curve to much smoother after introducing higher octane fuel.

Always open to other ideas so if someone can provide any links to info supporting octane vs burn rate I would like to read it