I just ran Portal again and recorded demos but for some reason it's writing data as if I'm playing on a mod (ex. from sourcemods folder), so when I playback the demo it says "directories don't match (portal / mod)" But it's running with nothing that's loaded from an external gamedir.
Okay, apparently this was because of the demoheader.tmp still containing data linking to the mod that was interfering. So I deleted it, created a new one and it works now. I guess let this be a precaution or requirement so people who both speedrun and play mods know what to do when trying to record demos or something. I hope I can also recover my demos if it's safe to replace the old header with a non-mod one.
Starting today, runs that require video proof (top 25) and runs beyond that where video is the only form of proof, now require audio, as recording audio for only the game is now a native OBS feature.