[pgAdmin4] Questions about trigger properties's Fires in edit mode

Hi, all

In trigger's Properties screen, the 'fires' is disabled.
What is the reason why 'fires' is disabled?
I think it should be the same as 'evnt_insert',
When server_type is ppas and in edit mode, 'fires' is disabled.

file: web/pgadmin/browser/server_groups/servers/databases/schemas/tables/triggers/static/js/trigger.js

 id: 'fires', label: gettext('Fires'), deps: ['is_constraint_trigger'],
          mode: ['create','edit', 'properties'], group: gettext('Events'),

disabled: function(m) {
            if (!m.isNew())     ★ In edit mode, 'fires' is disabled.
              return true;  
            // If contraint trigger is set to True then only enable it
            var is_constraint_trigger = m.get('is_constraint_trigger');
            if(!m.inSchemaWithModelCheck.apply(this, [m])) {
              if(!_.isUndefined(is_constraint_trigger) &&
                is_constraint_trigger === true) {
                setTimeout(function() { m.set('fires', 'AFTER'); }, 10);
                return true;
              } else {
                return false;
              }
            } else {
              // Check if it is row trigger then enabled it.
              var fires_ = m.get('fires');
              if (!_.isUndefined(fires_) && m.node_info['server']['server_type'] == 'ppas') {
                return false;
              }
              // Disable it
              return true;
            }