Just a historical note - no criticism intended.
the origins of dauls were in HAVING to have separate text and graphics monitors in the early days. When this need went away the majority of users quickly honed in on singles. Aplicon Bravo were the last hold-out and bet the farm on "old fashioned" duals...... and virtually bought the farm because of it. That had a lot to do with their choice of graphics chip also on the financial level.
Never the less you are in the minority of people who like duals. BTW: Ergonomics studies will tell you it is terribly bad for your neck, etc. Which is in fact one one of the early reasons for the move to singles.
Anyway, glad there is a way for you, but don't look for lots of support from SW to push duals.
3/4 of all the Spam produced goes to Hawaii - shame that's not true of SPAM also.......