Flex-objects List view item template

Is there a way to customize flex objects list view using item twig templates?
Suppose we have a "contacts.yaml" blueprint with the following list view part:

YAMLCopy

# List view
list:
  title: name
  fields:
    published:
      field:
        type: toggle
        label: Publ
      width: 8
    last_name:
      link: edit
    first_name:
      link: edit
    friends:
      field:
        label: Number of Friends
        template: '{{ friends|length }}'

I would like to see a number of "friends" in the last data-column. The field "friends" has a list type. But the above code does not work for me. The "template" setting is ignored. Is it impossible? Help me, please.

@Alexander I suppose there is no possibility to define own templates for normal list view items rihgt now. There is just a template property for the title field. However, I have a similar need for this feature right now.

Maybe anyone else has an idea for this issue?

Not sure if that's what you're looking for, but here's my plugin to show Flex Objects as JSON. Every view template is overridden and instead of HTML view all lists and items are shown as JSON