I have no giant hole in my gear shifting pattern, with a 48/32 and 11-34 12 speed. If you're doing any climbing that amounts to anything, you should always be in the little ring to start with, so you can progress from 17-19-22-25-29-34. If a 32/34 isn't low enough then a 46/30 or even a 44/28 crank might be needed.
When I do shift between the chain rings, I always make a 2 sprocket shift, immediately, so I'm in approximately in the same gear ratio as before the shift. With Campy, that takes one push of the finger lever or thumb button and about 1 second. My old 53/39/28 triple didn't work that much differently. A 1-cog shift isn't much easier or faster than a 2-cog shift.