I'll be more direct then - this run is NOT real, which should be obvious to anyone who has seen the video or read the runner's comment that I mentioned. It was posted as a joke in our discord after an aspiring speedrunner came up with an idea to use W3's world editor in the speedruns, and it was created by modifying the game files. However, there are several russian youtubers in this discord, and one of them saw the link to this run. He either didn't get the joke, or just decided to clickbait anyway, and decided to make a video which popularized this "speedrun". By now, his video has over 1 million views and by now, he edited the video's description and top comment to let the viewers know the run is fake.

I believe that we should change the rules to make sure that this is impossible - for example, not allowing the speedrunners to attack any pigs during the run should be enough to prevent any memory manipulation. The other option is to change the rules the way the runner himself suggested in the top comment of the video (it's in russian, you might need google translate).

I imagine that the reason why this campaign is not included in the all campaigns category (and why it is in misc) is that it is very different from the rest of the campaigns and some potential runners who might might only enjoy the RTS part of the game, not the RPG. However, I agree with moving it out of the misc, and maybe adding a misc category "all campaigns + rexxar" if someone wants to run it.

Rules: I would add one more rule - the run must be done on a new in-game profile, and the creation of this profile must be shown in the video. This is because the saved sub-maps are tied to your profile, not your current playthrough, and I suspect there would be some exploits abusing this fact.

the runner reset the run and switched to hard difficulty about 30 seconds later

Even if there were rules before the first run appears, they probably wouldn't say more than when you should start/stop the timer - and you don't really need to care about that, at worst mods will add a few seconds to your time. The only problem would be measuring IGT, but again, that's not really needed until there are more runners who have different loading times.

However, just to be sure, I would create a new w3 profile for every attempt (and show it in the video), just in case someone discovered something weird about the transitions between the maps.