With a minor change into extension code, verses could be wrapped into span tags.
Advantages: any verse would be retrieved as a html entity; anchors (like that built by it.source tl|§) will point precisely to a verse and to highlight precisely the quoted verse; it would be simpler to count them and to apply a dynamic verse numbering.
Disadvantages: now the poem block is a single span, and can be simply formatted as a single block (ie with <i> or <b> html tags); the trick will fail when a verse is brocken in parts into different lines.