The useragent string for edge browsers used to contain the word Edge. But now you get Edg without the e. So in the file /include/adpatives.php you can change this array definition.
//from
$browsers = array(
'KHTML' => 'Konqueror',
'Epiphany' => 'Epiphany',
'Opera' => 'Opera',
'Flock' => 'Flock',
'Firefox' => 'Firefox',
'Netscape' => 'Netscape',
'FireBird' => 'Firefox',
'Phoenix' => 'Firefox',
'Edge' => 'Edge',
'Chrome' => 'Chrome',
'Safari' => 'Safari'
);
//to
$browsers = array(
'KHTML' => 'Konqueror',
'Epiphany' => 'Epiphany',
'Opera' => 'Opera',
'Flock' => 'Flock',
'Firefox' => 'Firefox',
'Netscape' => 'Netscape',
'FireBird' => 'Firefox',
'Phoenix' => 'Firefox',
'Edge' => 'Edge',
'Edg' => 'Edg', //added
'Chrome' => 'Chrome',
'Safari' => 'Safari'
);
The you can use the following in smarty templates
{if $config.UA.browser eq 'Edg'}
{/if}