How to add tags with true/false value to Yandex market upload to Bitrix?

Question

1C-Bitrix

Good afternoon! I am uploading for Yandex Market on the site. There is an infoblock with goods on the site, in it the Availability field in the form of a list with the values: Showroom, In stock, On order. For products with the status Under order in the admin panel, it is necessary for the tag in the upload for Yandex Market to be substituted, that is, like this: false, and for the tag false. And if the status is Showroom, then true false. It is necessary for each product to set the set handler to false, true, for example, if the status is On order, then the property is false and this property should be pulled up in the price already. I tried to add the output of a new test tag, write the handler in the yandexrun.php file in the /bitrix/modules/catalog/load folder, copy it to another location /bitrix/php_interface/include/catalog_export, but nothing changes and it is not possible to test the changes or No,