How best to resolve Wordpress theme / CiviCRM conflicts
After inserting some debug code per recommendation at chat.civicrm.org, I discovered an even more focused repair is to just change a single line in civicrm_in_wordpress_set() within civicrm.php.
Replace


  $page = get_query_var( 'page' );


with


  $page = $_GET['page'];


and all problems we have noted disappear. The get_query_var call involves calls to our theme (looking at the backtrace at that point) that evidently get in the way. Obviously a theme interaction, but how would I even notify Benevolent support of the conflict? It seems so simple to make this one change on the CiviCRM side, but I need to understand unintended consequences. Why was get_query_var added in the first place - it first appeared in Civi 5.13.0?