I'm sure to most, this is a 'no duh' situation but throwing my hat in for the approval vote regardless. If there are any die-hard 9 speed friction fans out there like me, this might be of interest.
Before I thought:
A) the Silver DT shifters don't pull enough cable to fit 11 speed
B) I'd be spending the majority of the ride feathering the gears
Wrong and wrong. It works shockingly well, perhaps even better than 8-9 speeds perhaps because there's simply less room to mess it up. Now I probably wouldn't enjoy it as much with shifters that didn't utilize the ratcheting system since I can feel how the ratchet sorta auto-corrects the right engagement point when I'm changing gears but that's a topic of personal taste.
My setup is an Ultegra 6800 long cage rear mech, 11 speed chain, 11-34 105 cassette, and a Grand Cru 50.4 46-30 crankset.
Obviously the downside of all this is cost but if anyone was building up something new and was 11 speed friction curious, give it a shot!