Disable theme debug.. just in one field
No, this is not possible.

You would need to hack core in order to do it (twig_render_template), which might be ok for your local development.

The code in interest is this part:

if ($twig_service-&gt;isDebug()) {
  $output['debug_prefix'] .= "\n\n&lt;!-- THEME DEBUG --&gt;";
  ...
}


You could add a condition, like this:

 if ($twig_service-&gt;isDebug() &amp;&amp; $template_file != 'awesome-template-file') {


I'm not sure what $template_file looks like, but I'm sure you could use it to make a condition to make the template file in question be skipped debug. This actually requires that the field uses it's own template file though.