Exporting from LO Writer via Save As docx would give something like
Code:
<p class="quote">“—the vastness, profundity, and unsearchableness of His works, <span class="emp">which have a depth in them greater than the well of Democritus.</span>”</p>
Some might argue <blockquote> is semantic info. But often it's just a different paragraph style, a hangover from HTML3 or something.
Any change within <hn>, <p> or <blockquote> is always needing a <span>
Consider editing odt files in LO Writer using paragraph styles and an "export" via Save As in docx for Calibre (don't open the docx in LO Writer).
All the paragraph styles map 1:1 to <p> with 1:1 CSS and all character styles map 1:1 to <span>
I use Edit Span & Divs tool to fix back any <p class="some heading" etc to be <h2 class="some heading" etc, less than a minute.