If you want to take responsibility for adding line break formatting to all entries, you could change
titlepage_entry.
From the
Custom Output wiki page:
Code:
## ${id}, ${label}, ${value}
titlepage_entry:<b>${label}:</b> ${value}<br />
It might work to change the br to have a class containing the id and then apply a CSS to that class to
not have regular line break behavior:
Code:
## ${id}, ${label}, ${value}
titlepage_entry:<b>${label}:</b> ${value}<br class="te_${id}" />
add_to_output_css:
br.te_seriesHTML { display: none; }
I haven't tested that beyond Calibre Edit book.
It may not be that simple.