Just for the hell of it I turned off IPv4 and just left IPv6 running on my public interface on my computer.
It's interesting to see what actually loads. My Exchange client still works, but office265.com doesn't. The Microsoft store works though, so I guess there are priorities, lol! Facebook works, most google stuff works. I'm using google IPv6 DNS though, so maybe they are discriminating... Most of my bank URLs do not work. Ebay doesn't work either. Amazon no worky. Youtube works, but interestingly a lot of their inline ads don't, so maybe that's a bonus. My own website doesn't work. Sonar works, as does my front page of my billing portal since I enabled IPv6 myself on it. DigitalOcean works. My response and routing for things that do work seem a lot better. Blizzard launcher doesn't connect at all, so online gaming is out for that set of games anyways. Speedtest.net doesn't work. Most of these are saying ERR_NAME_NOT_RESOLVED or something similar with DNS like DNS_PROBE_FINISHED_NXDOMAIN