I've seen pros using hand positions as uncomfortable and unreasonable as some of mine just in order to stay on the thick part of the white keys because in those cases it was impossible to play otherwise. The climax of Chopin's Ballade Nš2 is a perfect example: all whites, yet you can't possibly play that sort of passage at that speed in between black keys. The result: you contract your hand to an awful possition, an still your pinky and (specially) your thumb end up pushing the very last milimetres of the white keys. And all of this for what? Who knows.
I get that, but still I don't see how could longer white keys possibly harm those who have small hands. I mean, you could just keep using the part of the key you were using before, and ignore the added length.