Changing The View Background with a template url

I’ve been building a custom interface for the living room chromecast here, since the default chromecast idle interface is very lacking in info, and not very personalised. I have the entire UI set up by now, however, I haven’t been able to figure out how to change the background of the view using a variable url. My idea was to make a template sensor that would randomly pick out an image, and use the value of that sensor in the following part of the yaml file of the view.

background: >-
  center / cover no-repeat fixed
  url('https://live.staticflickr.com/8047/8105512307_f11f2c4339_b_d.jpg')

Simply putting in a template in the url does not work, and leads to a white background. Same when I try doing it using the lovelace_gen integration:

# lovelace_gen
title: Home
#views: !include mytestview.yaml
views:
  - theme: chromecast
    title: HUD-gen-test
    background: >-
      center / cover no-repeat url("{{ states('input_text.background_link') }}") fixed
    path: hud-empty
    icon: mdi:television
    type: panel
    badges: []
    cards: []

I had hoped using the media background integration as a workaround would work, however it appears that it isn’t supported anymore from what I could find. Can anyone help me out, or at least tell me if this would be possible at all?