I had those "Travel Agents" installed when the bike was built up for me 20 years ago. I had specified "V" brakes and the STI shifters, and was told by Airborne that the travel agents would be required to match the levers to the brakes. At the time, I knew nothing about such things, so I agreed.
Things turned out well. Apart from a somewhat goofy appearance, they work perfectly. The brakes have a very smooth, progressive feel, and there is plenty of stopping power.
I didn't install these things myself, so I can't comment on the level of difficulty, but it looks like the hardest part is routing the cable around the pulley. I believe they can work to either increase cable travel (as in my case, and yours), or decrease it... so the cable "wrap" must be done right. I'm guessing it's not too hard.
Attached is an image showing the TAs.
"Travel Agents" may be seen close to the brakes. They look goofy (according to some), but work well.
Last edited by sweeks; 01-02-22 at 11:04 AM.
Reason: To correct for "goofy". :-)