A lot of naysaying in the early responses here. 16t the max that can be done? In 2016? 50 years ago Peugeot was doing that with hard to shift 3/32" chains, no pins or ramps on the teeth and a crude rod front derailleur.
Try it! 50-28 ought to be doable. 52-26 would be fun! 2:1! I'd pick the ring I had to have and just start playing with to other and see how far I can go. Indexing may be a struggle, esp for the upshift. (I will point out that front derailleurs don't lift the chain at all. They push the chain into the path of the teeth of the large chainring. The chain hitting or dragging on the bottom of the derailleur cage in small-small cogs is only an issue if 1) it catches on the cage. (Now that is a real problem. Very fast destruction of the derailleur.) 2) The noise bugs you and 3) Wear to the cage when you use those gears is unacceptable to you or your wallet.
I have used smaller derailleurs than the chainring difference called for many times, running a 53-42-28. I will happily run the 28-13 for a stretch of flattish road on tough climbs rather than double shift twice. Some of those front derailleurs went a long ways despite doing that. (Actually, you probably won't be doing much of that since a large small-small cross-over and a big chainring difference = an automatic shift into a much bigger gear!) What could be a challenge is index shifting which I guess is your current mode. You can step back a few years and install a friction derailleur for the front, perhaps a downtube of stem shifter mounted on the aero bars (if this is for the Fuji Aloha of your intro). Get the SunTour ratchet shifter if you can find one. It will come as a double; I doubt it was ever made as a front only and I don't think I have ever seen a rear only. That shifter should be perfect for the huge shifts you are talking.
Also, use a chain catcher. I use the Deda one and the one that started it (whose name I forgot) on my three triples. If you Google "chain catcher" you will see options that didn't even exist last time I looked.
Ben