When only the first value is needed (or expected) instead of iterating
over the array, it is possible to access the values by adding "_first."
before the variable name.

Example: {{r.modelFile._first.varname.value}}

Instead of

{%for row in r.modelFile%}
{%if forloop.first%}{{row.varname.value}}{%endif%}
{%endfor%}