About the only place to find current "Q" numbers is in a current Rivendell catalog or perhaps at their website.

A double will save you about 9mm of "Q" in comparison with a triple, as long as you change the crankset and the BB spindle.

Once you have decided to use STI and use production margins, there are few ways left to reduce Q. Here's why:

1. You have to have margin to drop the chain between the inside ring and the chainstay. Otherwise, with soft materials, and to a lesser extent with steel, the chain will remove material from the chainstay.

2. STI requires certain spacing between the rings.

3. STI requires certain minimum spacing between the outside ring and the inside edge of the crankarm to allow for the function of the FD.

So the only ways to reduce crankset "Q" with STI, after the number of rings is set, is to 1) reduce the margin between the inside ring and the chainstay below production margins, or 2) to find a crankset with laterally thinner crankarms (never heard of such a thing, but why not? With high-technology materials it should be possible), or 3) offset the pedal centers by running the margin on the left side down to zip (no chain there, possible fit symmetry issue for some people, though). It turns out that shoe dimensions tend to prevent reduction of pedal Q. Any reduction of pedal effective spindle length tends to run the inside of the shoe into the crankarm.