I notice everything about how people ride most of the time. Well, not everything, but a lot of stuff, including backside/frontside, toeside/heelside. I learned bri's heelside/behind me. I can still buttercup toeside (obviously), briwhip/briheelwhip heelside, and catch bri's really easily. Capron Funk, Josh Kish, and I'm sure a lot of other people do them this way. I do every scooterflip on my heelside actually, although I almost have toeside front scooterflips.
And yeah, Josh did do a double "oppo" bri but I wouldn't consider it opposite because he learned them that way.