Should I reach into the Django _prefetched_objects_cache to solve an N+1 query?

I have the following Django template code with an N+1 query:

{% for theobject in objs %}
  {% for part in theobject.parts_ordered %}
      <li>{{ part }}</li>
  {% endfor %}
{% endfor %}

Here is parts_ordered on TheObject:

  class TheObject:
    # ...
    def parts_ordered(self) -> list["Part"]:
        return self.parts.all().order_by("pk")

And here is the Part object:

  class Part:
    # ...
    theobject = models.ForeignKey(
        TheObject, on_delete=models.CASCADE, related_name="parts"
    )

and here is the prefetch getting objs:

    ofs = ObjectFormSet(
        queryset=TheObject.objects
        .filter(objectset=os)
        .prefetch_related("parts")
    )

I think the order_by("pk") disrupts the prefetch.

This is what chatgpt recommends, and it works (no more N+1 queries, results seem the same):

  class TheObject:
    # ...
    def parts_ordered(self) -> list["Part"]:
        if (
            hasattr(self, "_prefetched_objects_cache")
            and "parts" in self._prefetched_objects_cache
        ):
            # Use prefetched data and sort in Python
            return sorted(
                self._prefetched_objects_cache["parts"], key=lambda cc: cc.pk
            )

        # Fallback to querying the DB if prefetching wasn’t used
        return self.parts.all().order_by("pk")

Should I rely on _prefetched_objects_cache? Is there a better way?

from django.db import models  
  
  
ofs = ObjectFormSet(  
    queryset=TheObject.objects  
    .filter(objectset=os)  
    .prefetch_related(  
        models.Prefetch(  
            lookup='parts',  
            queryset=Part.objects.order_by('pk'),  
            to_attr='parts_ordered',  
        ),  
    )  
)