I would rather Paradox spend time making the game engine better(something that is hard for modders to do) then spend the time getting the details right(something that is easy for modders to do).
So would I. I would just disagree on whether the taiping rebellion is "details." I'm not talking about a system to make sure the taiping rebellion happens, which could POSSIBLY take "a week," in arathian's words, but simply having it exist in 1861, "close enough" to being accurate for the time. I doubt simply adding the country, and giving it some troops would take someone familiar with the workings of the game more than a couple hours.