The display_name should also use the formatted_name.

app/models/dmsf_file.rb

@@ -403,10 +403,17 @@ class DmsfFile < ActiveRecord::Base
   end
 
   def display_name
-    if self.name.length > 50
-      return "#{self.name[0, 25]}...#{self.name[-25, 25]}"
+    member = Member.where(:user_id => User.current.id, :project_id => self.project.id).first
+    if member && !member.title_format.nil? && !member.title_format.empty?
+      title_format = member.title_format
+    else
+      title_format = Setting.plugin_redmine_dmsf['dmsf_global_title_format']
     end
-    self.name
+    fname = formatted_name(title_format)
+    if fname.length > 50
+      return "#{fname[0, 25]}...#{fname[-25, 25]}"
+    end
+    fname
   end
 
   def image?