Hi Brian,
You can try! But please review the logic as posted on the attached files of MDL-40065 first. And please look at how my Shoelace theme handles things.
Also examine the current code very carefully. There is a complicated switching mechanism going on, so even if the parameter in RTL is 'side-post' it ends up as 'side-pre'.
Given the way that MDL-40065 progressed the first time there needs to be a solid well substantiated argument. And even that might not work!
Cheers,
Gareth