So i've done this category with Hela about three times now just for fun and there needed to be a video when requesting a new category so;

The recording would need to start from the lobby, because it shows if you're queuing with people or not. Your run would be rejected if you would que with other people. The recording would end after showing the final time by clicking on your own profile and showing the previous match info and the final time would be shown there. (as shown in the video)

Few problems with the category could be that certain characters wouldn't be popular, especially with supports and tanks, because those roles aren't that fun to run in doom match. A potential fix could be; to only have the dps characters as speedruns and not add the rest.

-Afk players could be a problem or players that are not even trying to kill opponents, i think this one could be fixed by just rejecting those runs however.

The segregation between console and pc could also be a part of this category, but the different platforms honestly have a pretty even playing field, so i don't know. There's also that matchmaking setting "console only" which does make matches feel better to play.

Now i'm not sure if other people would be into this category, but i atleast would run many different characters.

Doesn't follow all your rules, but I didn't que with anyone. fastest doom match I can find.