That's pretty neat, sure, but you've also done a pretty good job proving @aclimatt right on a few points:
Broken back button: check. Broken scrolling: check. Broken accessibility: check.
Broken back button: check. Broken scrolling: check. Broken accessibility: check.
You'll have to weigh how much these affect overall user experience on various browsers and how it affects your business. I don't recommend people optimize for all platforms, because you will spend forever on it. It's perfectly fine to say "Ok, my site is only for iPhone users on iOS 10+ and Windows Edge 12+." or some limited subset of users.