You know that framing it like that is already presupposing a great deal about what conclusions one wants. In a taxation or draft frame, no one talks about whether the draftee or the combatant nation or tax-payers wants to be coerced; in a discussion of crime like mugging or murdering, no one talks about whether the murderer wants to murder.
The response to a frame like 'think of the woman's preferences' is to frame it another way, 'think of the famous violinist'. If the frames differ and the introduction of an 'exciting new emotionally significant detail' could possibly change your appraisal, well, you've learned something very important about your appraisal...
Sure, as I said, it's interesting that's how these analogies work — by inviting the reader to (for the sake of argument, of course!) zero out almost all of the salient real-world information about the act. They move us further from the real-world scenario and toward increasingly abstract contemplations of possible combinations of rights and obligations.
That's a wide-open invitation for bias — an invitation for each reader to pick and focus on whichever analogy fits their prejudices, instead of more closely examining the facts ... and in particular any fact...
A few years ago, I wrote a little dialogue I imagined between 2 materialists, one of whom was for and one against abortion, centering on the personal identity question. I recently cleaned it up and added a number of references for the biological claims.
You can read it at An Abortion Dialogue.
Early feedback from #lesswrong is that it's a 'nicely enjoyable read' and 'quite good'. I hope everyone likes it, even if it doesn't exactly break new philosophical ground.