I'm using Compact double cranks, 48 or 50/34. I also wax my chains
and don't oil them. The inward movement of the front derailleur is
adjusted to that it either grazes or just misses the inner cage in the
small/small combination. Derailleurs are Campy 10 but also used
Shimano DA, 105 and XTR 900.
I noticed that the chains dropped more freqently when the chain was
approaching time to rewax. I also read here that the big ring needed
to have any burrs smoothed. My chainrings are almost new.
I very lightly greased the teeth of the big ring and, voila, the chain
does not miss the small ring on the downshift. The grease picks up a
little dirt but nothing like an oiled chain.
The tandem, also a compact double, 50/34 x 12/34 has an N'gear Jump
Stop. That's the best way to go.