I've always been unhappy with the way original and modern transcriptions in the engravings are stored in separate annotations and linked to separate zones. I think a better approach would be to combine the two within one annotation, inside special divs that mark them as alternates:

<div type="transcription_alternates">
  <div type="transcription_orig">
    <p>[...]</p>
  </div>
  <div type="transcription_modern">
    <p>[...]</p>
  </div>
</div>

The XSLT could then provide a single pop-up annotation window with a choice of two tabs at the top or the bottom, so you could switch between them. It could even remember your preference (the last tab you looked at) in a cookie.

It might be possible to automate the conversion of the existing code to this new approach using XSLT; you'd have to identify zones which were equivalent (mostly overlapping), and rewrite the contents of the Transcription category so it contains both, then delete the modernized ones. I think this would definitely be a cleaner approach to providing both transcriptions.