As always, it's possible to achieve adding an interuption to bb_plugins.php (preferrably at the top of that file, before Captcha etc.):
if($action=='register' or $action=='registernew'){
$enableNewRegistrations=FALSE;
echo load_header();
echo ParseTpl(makeUp('registration_disabled'));
$endtime=get_microtime();
$totaltime=sprintf ("%01.3f", ($endtime-$starttime));
if(isset($includeFooter) and $includeFooter!='') include($includeFooter); else echo ParseTpl(makeUp('main_footer'));
exit;
}
Then under
templates/registration_disabled.html put any HTML and text regarding disabled registrations.
