Hide attributes if not available

A media_player can show a range of attributes depending on what it is playing - or not playing.
I want a card to only show the attributes that have information to display.
I have tried entity-filter but cannot find the operator/value that fits the bill.
Am I on the right track or what should I be using?
Eg. a media_player will have an attribute media_album_name if spotify is playing an album through that media player. However if the media player is not playing or is playing media from the TV it will not.

entities:
  - type: attribute
    entity: media_player.office
    name: Album
    attribute: media_album_name
  - type: attribute
    entity: media_player.office
    name: Artist
    attribute: media_artist
    icon: none
  - type: attribute
    entity: media_player.office
    name: App
    attribute: app_name
    icon: none
state_filter:
  - operator: "!="
    value: None
title: Lounge
type: entity-filter

Using the Developer Tool/Template I have to convert the attribute’s state to string to be able to compare it with anything.

{{ state_attr("media_player.lounge","media_album_name") | string == 'None'}}

Further research seems to show that the filter will remove/show the ‘entity’ where the attribute matches the filter. Whereas what I want is to filter the display of the entity’s attribute(s)…

Still stuck.