I've used a lever for a triple on a compact double crank for a couple of years with no issues. That same bike now also has a wide-range cassette (11-34) on it with an Ultegra dérailleur (6700 GS). The derailleur's capacity was the key number in determining if it would work with the cassetteI wanted to use. Previous model numbers wouldn't have worked for what I wanted to do.
2009 BMC Road Racer SL 01 / Specialized Ruby 155
2007 LeMond Reno / Luna Chix Team Saddle
1980-something Lotus Odyssey / Brooks Finesse
1992 Bridgestone RB-2 / Brooks B-17 Imperial
Nada Bike singlespeed / Brooks Team Pro in white