I remember back in the day there was either a setting to increase the size or maybe it was a UI mod, but I always tried to avoid every mod I could because I wanted to play the real version of the game.
Does anyone know how to do this?
sadly I cannot help u with that, my original suggestion would be an AddOn but as U already wrote ur looking for a specific mod - I cannot help 
just open the man and leave it open ?
That’s what I’ve been doing with my latest character. Sized it so I could keep it open off to the side.