If you want to forsee each templates with the option to either additional information and/or attachments, like this:
You can use below code as an example:
{% comment %}
below code gives the option to either input some extra info or add a file, or both
when nothing is added, this section will not be exported
- change the name of custom.some.thing into something proper like "custom.VAT.additional_info" and "custom.VAT.additional_file" for instance
{% endcomment %}
<br>
{% ifi custom.some.thing.document or custom.some.thing_2 != blank %}
{% stripnewlines %}
|----
|----
{% newline %}
| **{% t "Additional information" %}**
| {% input custom.some.thing as:file_collection %}
{% endstripnewlines %}
{% input custom.some.thing_2 as:text placeholder:'extra info' %}
{% endifi %}
The ifi-statement makes sure there’s nothing exported if there’s no files added or text inputted.