Regarding the general shortening of road chainstays and widening of rear axles in recent decades, yes. Regarding subtle differences in chainstay length among similarly purposed bikes, probably not. The difference between a 40.5 cm stay and and 40.8 cm stay is, um, three millimeters.

Regarding cross chaining, I've always considered the two smallest cogs in back NOPs when using the small ring up front. The chain drags on the inside of the big ring using the smallest, the small ring ins for climbing (using the slow end of the cassette), and there's so much redundancy in doubles and triples with 9-, 10-, and 11-speed cassettes that it's no great loss. I'm not saying don't ever use small-small, just don't be a pain in the neck to your shop mechanic because he can't stop that kind of chain rub without screwing up the chain line somewhere else.

Back in the day of 5-, 6-, and 7-speed cassettes there was more need to make every combination unique. These days, shifting is more about finding the right ring for the general attitude and playing the cassette for flexibility. And some riders like working compact doubles, some like standard doubles, and some like triples. Generally, the triple guys I've known use the small ring for the slow end of the cassette, the big ring for the fast end, and the middle ring for the whole deal. And triple guys love the flexibility of that middle ring, something I can't argue with. Going to a double, you're going to be shifting rings a lot more.

Regarding big-big, I occasionally use it. Modern chains are really flexible and sometimes I need a little more low end to get over a hump I underestimated, without losing too much speed dropping to the small ring or bothering with a double shift (down to the small ring and two or three upshifts in back). So arrest me, cross-chainng police.