{USERCLASSES} shouldn't display core classes like mainadmin etc

[Jimmi08]

On user-settings form {USERCLASSES} displays classes like Newsletter and users can assing themselves to them.
Only classes with edit access are displayed.

While this works nicely for regular users, it is very confusing for admins, mainly for the main admin (it displays all core classes and you can check them, but after saving they are unchecked again, but you still have access to those classes)

Could this be fixed?

My idea:
in shortcode - added "strip"
$ret .= $e_userclass->vetted_tree('class', array($e_userclass, 'checkbox_desc'), $inclass, 'strip,editable, no-excludes');

and then in this class after
`$perms = $this->uc_required_class_list($optlist,TRUE); // List of classes which we can display

		if (strpos($optlist, 'strip') !== FALSE) {
		    $b = array_flip($perms);
			$a = $this->stripFixedClasses($b);
			$perms = array_flip($a);
		}

A similar approach is used in the usersettings file when saving this to user data.

Result:

Note: all classes between 243 and 255 are removed.

Thanks