In almost each cases those globals have first priority:
Checked:
$NEWSSTYLE
$COMMENTSTYLE

But $NEWSLISTSTYLE is used this way:

		if(deftrue('BOOTSTRAP'))  // v2.x
		{
			$template = e107::getTemplate('news', 'news', 'list');
		}
		else  // v1.x
		{           
			if(empty($NEWSLISTSTYLE))
			{

$NEWSLISTSTYLE should have priority too before BOOTSTRAP, because others variables work this way.

Thanks