What is the usefulness of setting custom parameters to Django formset

I was reading through the documents on forms and formset when I came across customizing formset and form's init parameters. I quiet get the concept but I don't know any real life application of setting a custom parameters. Someone please broaden this for me.

I tried looking into some questions asked concerning custom parameters here on Stack overflow, I get the concept but I don't know any real application of passing custom parameters to forms and formsets

Imagine a game where a player can choose to attack his neighbors. Obviously every player has different neighbors. Every neighbor is also a player. For the attack-move the player needs to choose one neighbor out of these four.

Basically your form needs a dynamic ModelChoiceField. Dynamic hence every player has different neighbors.

class AttackForm(forms.Form, BaseForm):

    def __init__(self, neighbor_queryset, *args, **kwargs):
        super().__init__(*args, **kwargs)

        self.fields['neighbors'] = forms.ModelChoiceField(
            queryset=neighbor_queryset,
            widget=forms.Select()
        )

This allows you to pass the neighbor_queryset on the fly to the form. See another example for ModelChoiceField (here). They did not explicitly put queryset in the arguments of __init__, therefore you have to pop() it from the kwargs.