Edge has changed since I posted the original bit of code, the following is how the plugin needs to look now to force edge to work correctly.
Code:
//This plugin checks if the user is using Edge, if he or she is, it forces use of the standard editor
global $vbulletin;
{
if (strpos($_SERVER['HTTP_USER_AGENT'], 'Edge'))
$vbulletin->userinfo['showvbcode'] = 1; //This is the standard editor
}