Is it possible to use SSI with If Modified Since in Nginx?

Question

Server Side Includes

There is a page which is cached entirely. With the help of ssi set up a "window" for the hit counter.
<!--#include virtual="ssi/page_views.php" -->
config looks like this

location ~ /ssi/page_views.php$ {
  include fastcgi_params;
  fastcgi_pass unix:/run/php/php7.0-fpm.sock;
  fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
}

location ~ [^/]\.php(/|$) {
    fastcgi_split_path_info ^(.+?\.php)(/.*)$;
  if (!-f $document_root$fastcgi_script_name) {
    return 404;
  }

  ssi on;
  ssi_last_modified on;
  
  include fastcgi_params;
  fastcgi_index index.php;

  	# Backend server
  fastcgi_pass unix:/run/php/php7.0-fpm.sock;
  
  fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
  fastcgi_param QUERY_STRING    $query_string;
  fastcgi_param HTTP_IF_NONE_MATCH $http_if_none_match;
  fastcgi_param HTTP_IF_MODIFIED_SINCE $http_if_modified_since;
  
  ##
  # fastCGI Cache
  # Включаем кэширование и тщательно выбираем ключ кэша.
    ##
           
    # выше за данным примером кофига устанавливается skip_cache когда необходимо не кэшировать
    fastcgi_cache_bypass $skip_cache;
    fastcgi_no_cache $skip_cache;

  fastcgi_cache wholepage;
  fastcgi_cache_valid 200 301 302 304 5m;
  fastcgi_cache_key "$request_method|$http_if_modified_since|$http_if_none_match|$host|$request_uri";
}

If we leave the 'ssi_last_modified on' last modified header returned, the server returns a 304 status and ssi is down. Whether probably, that and 304 gave and dynamically the counter worked?