> To be clear, this is declaring that $textNode.traversingMethod() always yields an empty collection—a breaking change with respect to 1.9.0—for compatibility with current state of 2.0 beta.

Ugh. I think that's a critical point, we're introducing a pretty big behavior change 1.9.0 to 1.9.1. If this was 1.9 I think it would be easier to advocate this change. Also, I don't think we've ever said we support document fragments in all APIs but this is letting them through. 

Is there any reasonable middle ground?