I am asking if this could be used for endless speedruns. There's an unused feature that can be easily accsessed through console commands which I have written in the "Guides" section. Instead of having a huge file size and long upload speed for people with bad connection, the demos are a good alternative for uploading endless runs due to their length. It's also good for those who have barely any space on their computer too. Unlike a mp4, a demo allows you to look at the player from different perspectives as well as where the zeds spawn, etc. It's very interactive.

So there is a few potential issues I foresee with this because of how reply systems in game have been before and how they act. They may not be as accurate as a live recorded run, they can be altered or tampered with much easier then a live run would be or less noticeable if done so. There is other things as well but I'm not saying any of this is true for KF but we would need to as a group explore it more before making an allowance on runs that were not a recorded live attempt.

The most noticable downsides is that just like spectating a player on a server, you can't see their viewmodel when first person. While it is possible to show the hud because its set to off by default, you will not see the result screen pop up at the ending. Recording demos on multiplayer will crash your game so this is limited to solo only. To see the hud, you will need to enter "ShowHud" command into the console when watching the demo. You can hear the firing sounds of the weapons, tho there exist some weapons that don't have sound. You can see the health of the player from showing up the scoreboard, as well as the perk and level.

Ok, turns out I was wrong about multiplayer crash when using it, sort of. Log in as a server admin and do "admin DemoRec" allows you to record a demo in multiplayer. Use "DemoRec" into the webadmin's console if you want to start recording from webadmin. The file doesn't store in your client-side when recording from multiplayer, but in the server-side instead. The server's path is KF2Server/KFGame/Demo. You do "DemoPlay" from ingame console. I updated the guide to include this information.

EDIT: Appearently some people can do the "DemoRec" command in multiplayer without begin logged in as admin. This is really weird. However, if you do that, then you will be able to load the map and shortly after in a few seconds, the demo will automaticly end even if it wasn't supposed to end, so maybe it got soft-corrupted as a result of this. When I was done doing that in mulitplayer and I tried demorec in solo, my game crashed which makes me more confused. I launched my game again and immediately went to solo to record a demo again but it crashed. I think it crashes on one of the two (solo or multiplayer) based on where the demos could be stored, but that's just an uneducated guess. Strange thing is, before I did recorded a demo in multiplayer, a while ago I did record multiple demos in solo, so in that case the demos must of been switching places in the file locations automaticly. I have no idea, just guessing at this point.