I can't seem to find anything that mentions what difficulty the speedruns are on. Could someone please tell me?

I've been playing on Medium, but not sure what the times are posted against.

Thanks

Been doing glitchless runs and I have a few questions.

In LiveSplit, I see that there is an auto split for Doom. I activated it and my in-game time is getting logged, but I noticed in BlackChaos' run, it is in real time with loading screens and menuing. I didn't see anything specifically in the rules on timing so I am not too sure what the proper timing method is, but have been assuming real time. Is that correct? I mainly ask because there's like a 6 minute difference between my real time and game time.

My other question is on the final GK. Rule states the timer ends when the GK is performed. Is that as soon as the GK starts or when it ends? Again, I only see BlackChaos' run so I am assuming everything he did in that run is now set in stone, but I just want to make sure so I split properly. I thought I understood the rules, but just finished watching his run this morning on my commute and saw the late split.