This part:
<?php if (isset($quantity_taxation_curr) && in_array($currency['code'], $quantity_taxation_curr)) { ?>
to become in twig format, i tried with this one:
{% if isset(quantity_taxation_curr) AND in_array(currency['code'], quantity_taxation_curr) %}
But it's not correct.
Try this:
{% if quantity_taxation_curr is defined and currency['code'] in quantity_taxation_curr %}
Try this out
{% if quantity_taxation_curr is defined and 'code' in quantity_taxation_curr %}
...
{% endif %}