Obviously, I'm not the best person to be speaking about this, but I can only re-iterate what others have said about being very, very specific about one's interests--and, if not, making sure to explicitly wrangle in advance with the imagined-puzzled-looks that adcomms might have about your SOP. I reckon your supposition about turning off both prosodists and early modernists with your articulation of your interests might be correct.
I had to make a choice to apply as an early modernist (since that's where the bulk of my work has been) even though my more recent passion has been modern American cultural studies. When I corresponded with POIs, I always asked how they felt about these two disparate interest. The schools with the POIs that said they saw it as a strength (in an interdisciplinary way) or advised that I devote a section of my SOP to explaining the (what they said was an exciting) theoretical confluence between the two fields were, not surprisingly, the schools at which my app had the most success. The schools that seemed a little more confused or less enthused about my disparate interests rejected me probably for that reason (among others).
On the subject of app season self-reflection, I don't think my SOP or my way of articulating my interests was what held me back: it was a crappy WS. I wrote it in about two-three weekends during a busy stretch of a semester. If I had more time to fine-tune it and fix up obvious problem areas, I think I might have fared a bit better.
PS. I do want to ask you as well about your WS: you say it was based on intentionality in three of Shakespeare's sonnets. Does this WS actually demonstrate skill in transhistorical prosody? It seems rather confined to the early modern period.