Continuing the discussion from Standardizing innerText:
Just to start the ball rolling, I'm thinking the sanest way to handle some of the most significant disagreements on selection behavior (how should whitespace be translated, should text transformations be applied) would be to add CSS rules controlling it (and then specify what the default values for those rules should be).
Such a rule would be akin to (and maybe extended from) the non-standard
user-select rule. (I was originally thinking of properties on
document in the DOM that could be set by script, but a CSS rule like this makes more sense, especially as it allows this behavior to be declarative and element-oriented.)