How to Output Realtime Computed Field Value
&quot;How do I output a computed field value in real time?&quot;
The answer is that you cannot.  The Computed Field module updates the value on entity save.  So, to get the most recent value, you have to save the entity.
If you are trying to show a value that you compute in a view, computed field is a bad solution because you will have to re-save all the entities whenever you display the view, which is horrible for performance.
Alternative solution idea
Since you're doing calculations based on time, one option might be to use Views filters.  Make a primary view that shows the default pins, and then embed or attach additional views that have filters that are set to find the pins for ending_soon and starting_soon.
If you need to override the Views filter calculations, you can do that in hook_views_pre_view():
Here's a code example from one of my sites where I override the filter value to use &quot;midnight for the logged-in user's timezone).&quot;
function MYMODULE_views_pre_view(ViewExecutable $view, $display_id, array &amp;$args) {
  if ($view-&gt;id() === 'my_view' &amp;&amp; ($display_id === 'my_display') {
    $filters = $view-&gt;display_handler-&gt;getOption('filters');
    if ($filters['field_datetime_target_value']) {
      $user_timezone = date_default_timezone_get();
      $current_timestamp = \Drupal::time()-&gt;getCurrentTime();
      $midnight_usertimezone_datestring = MYMODULE_get_midnight_datestring(&quot;$current_timestamp&quot;);

      $filters['field_datetime_target_value']['value']['value'] = $midnight_usertimezone_datestring;
    }
    $view-&gt;display_handler-&gt;overrideOption('filters', $filters);
  }
}