It should work…
As said above, it will require you to adjust the limit screws on the front mech to allow you change correctly.
I’ve not setup a double on a triple changer, but would have thought that you would adjust the inner limit screw to allow the changer to drop down to access the inner chain ring, then position 2 would shift you to the outer chain ring, and using the outer limit screw adjusted just a little further out, you could use the position 3 as the trimmming position for the outer ring to stop it rubbing the mech on the small cassette rings.