How can I add nested product attributes in Product Feed pro?

General
1

I am generating a product feed for Marktplaats (Example feed) in the product feed pro plugin for WooCommerce.

Product feed pro has a preset Marktplaats feed, but it misses some necessary attributes. This would normally not be an issue because you can easily add product attributes, however I need to add nested attributes.

Here is an example of one of the nested attributes I need to add:

 <admarkt:shippingOptions>
            <admarkt:shippingOption>
                <admarkt:shippingType>PICKUP</admarkt:shippingType>
                <admarkt:location>1097DN</admarkt:location>
            </admarkt:shippingOption>
            <admarkt:shippingOption>
                <admarkt:shippingType>SHIP</admarkt:shippingType>
                <admarkt:cost>695</admarkt:cost>
                <admarkt:time>2d-5d</admarkt:time>
            </admarkt:shippingOption>
        </admarkt:shippingOptions>

I have added the custom attributes to the products with the advanced custom fields plugin. Field groups are generated and work fine. The child attributes show up in the Product Feed pro plugin, but I need to map the whole nested group, as shown in the XML example above.

What I’ve tried

I have tried editing the php file to enable the nested group for specific groups (like shippingOptions), but to no avail. I have also exhausted all the options within the plugin itself.

Important detail

The plugin has built in nested groups the look like this:

Plugin:

plugin shows the child fields entered, no parents need to be selected

The XML then looks like this (which is correct):

<admarkt:budget>
<admarkt:totalBudget>20</admarkt:totalBudget>
<admarkt:dailyBudget>5</admarkt:dailyBudget>
<admarkt:cpc>0.09</admarkt:cpc>
</admarkt:budget>

There must be an easier way that I am overlooking to add custom nested product attributes than editing the php., just like the plugin already automatically sets up for fields like budget. I must be overlooking something childishly easy.

Question How can I add nested product attributes in the Product Feed Pro plugin (asking here because support takes days).