title: Plotly Express hover options
body: <p>In <code>plotly_express.line</code> the only options I see to modify hover settings are <code>hover_name</code> and <code>hover_data</code>. A few issues I'm facing with modifying hover are:</p>
  
  <ol>
  <li><p>It seems that even if I set <code>hover_data=None</code> it still shows the values for <code>name</code>,<code>x</code>, and <code>y</code>. How can I set it to <em>only</em> show the hover info I select without adding defaults?</p></li>
  <li><p>I can't find a setting to modify the opacity for hover boxes. I'm displaying a lot of hover info so my hover box is large, which makes it difficult to know where I am on the plot behind the box.</p></li>
  <li><p>How can I make it so hovering on one line displays hover info corresponding to a linked data column value on all other lines?</p></li>
  </ol>