One round of my method is 5 minutes long. You need to be actively playing, but it's not difficult at all

Squire is 1000 points ( 6 rounds/30 minutes)
Knight is 2000 points (+7 rounds/35 minutes)
Lord is 3000 points (+9 rounds/45 minutes)
King is 4000 points (+13 rounds/65 minutes)
High King is 5000 points (+29 rounds/145 minutes)

The more points you have, the slower it get. At the end, you will only obtain 20 points per rounds.

You will need at least one controller. I recommend a secondary monitor and 2 controllers to not get bored too much.
The tar boulder and paint one. If you don't have them, play story first or download a completed save file here https://cs2bus.com/app/434460/discussions/0/1699415798760403913/

After launching the game, with a controller add a guest.
Go online (right) and disable "public" setting.

Create a war game in the Oxfordshire map (because it is a simple and short one)

Be sure to play against the guest, and no AI is involved, so choose different teams.
Choose whatever rock for the guest, but choose the tar and paint boulders for you.

Match begin :

Choose tar boulder, wait 1m20 and hurt the door. Repeat once more
Choose paint boulder, wait 50 sec and destroy the door. Crush the guest

Restart match !



Tips : if you play with two controllers and a secondary monitor, the game will still work without being the active window, so do what you want at the same time. (use borderless, in the option of the game)