Not sure why the references to cross chaining.
Looking a gear calculator with my favorite 12-27 cassette, the 34-14 is very close to the 48-19, no cross chaining required. It is a bit odd to have to shift the rear a couple of gears when you shift the front.
8 speed works about the same with the 14 and 21. Even the 6 speed doesn't require cross chaining.