I have a full Ultegra 6700 triple gruppo that I would like to be able to use as a double of either flavor as well. The $500 question is will this require procuring a set of ST-6700 double specific shifters. I plan to replace the FD, obviously, and possibly the RD though the latter has advantages in cassette size for a double. I have some credible reason to believe it is possible here. In the specs panel it lists double/triple in the front shifting column.

I was aware of Campy having this capability but not Shimano. In my defense this is my first modern road bike and Dura Ace 7400 was formerly the most current shifting I had used. If this is merely a matter of setting the FD to only have cable tension in two of settings before being ineffectively slack please feel free to point out that it is just that simple. Thank you and crossing my fingers I can really get by with just changing a derailleur and cranks.