Default value does not pull through like normal

Had to write my own code by editing the plugin. Line 123 in Hidden.php
I assume this code is bad and might have issues, possibly security issues so use at own risk:

if ( (is_array($value) && is_empty($value)) || $value == "" ) {
$value = isset($GLOBALS['_POST'][$tag->name])?$GLOBALS['_POST'][$tag->name]:"";
}

If there is anyone willing to add a better solution please do so.

Sorry, for my stupid question, but does this also work with values taken over by a “GET”-URL; example:

https://conserve.de/bestellung/?Customer_Number=10000&Customer_Code=CNS

I posted a question regarding this here:

https://www.ads-software.com/support/topic/fill-hidden-field-via-defaultget?replies=1