Templating icons in customize section

Feature Requests
1

I would really like to be able to template icons in the customize section.
At the moment this seems only possible in the sensor section.

Example:

  customize:
   script.radio538:
    friendly_name: Start Playing
    icon_template: >
            {% if is_state("input_select.radio_station", "Radio 538") %} http://snowminds.nl/wp-content/uploads/2015/03/Logo-Radio-538.png
            {% elif is_state("input_select.radio_station", "Q-Music") %} https://www.perssupport.nl/uploads/press-news-item/original/7562687e-7fe4-11e1-8543-b971b6abc044.jpg
            {% else %} mdi:play
            {% endif %}
2

+1,
Being able to add a custom picture to a chromecast stream would be great. Could be extended to tts and any other media played