This will add a progress bar to conditional media cards. Add progress_bar.yaml to button_card_templates directory. Add the lines from themes.yaml to themes.yaml. Add - progress_bar to conditional_media cards in ui-lovelace.yaml

progress_bar.yaml

progress_bar:
  styles:
    custom_fields:
      progress:
        - background-color: var(--progress-bar-background-color)
        - position: absolute
        - left: 0%
        - top: 73.9%
        - height: var(--progress-bar-height)
        - width: 100%
      bar:
        - background-color: var(--progress-bar-color)
        - position: absolute
        - left: 0%
        - top: 73.9%
        - height: var(--progress-bar-height)
        - z-index: 1
        - transition: 1s ease-out
  custom_fields:
    bar: >
      [[[
        if (entity.attributes.media_position !== undefined) {
        setTimeout(() => {
          let elt = this.shadowRoot,
              card = elt.getElementById('card'),
              container = elt.getElementById('container'),
              bar = elt.getElementById('bar');
        
          if (elt && card && container && bar) {
              card.insertBefore(bar, container);
                function update() {
                  let mediaPositionUpdatedAt = entity.attributes.media_position_updated_at,
                      mediaPosition = entity.attributes.media_position,
                      mediaDuration = entity.attributes.media_duration,
                      mediaContentID = entity.attributes.media_content_id;

                  let percentage = entity.state === 'paused'
                    ? (mediaPosition / mediaDuration * 100)
                    : entity.state === 'playing'
                      ? (((Date.now() / 1000) - (new Date(mediaPositionUpdatedAt).getTime() / 1000) + mediaPosition) / mediaDuration * 100)
                      : 0;

                  percentage = Math.min(percentage, 100);

                  bar.style.width = percentage.toFixed(1) + '%';
                  requestAnimationFrame(update);
                }
                requestAnimationFrame(update);
          }
        }, 0);
        return ' ';}
      ]]]
    progress: >
      [[[
        if (entity.attributes.media_position !== undefined) {
        setTimeout(() => {
            let elt = this.shadowRoot,
                card = elt.getElementById('card'),
                container = elt.getElementById('container'),
                progress = elt.getElementById('progress');

            if (elt && card && container && progress) {
                card.insertBefore(progress, container);
            }
          }, 0);
        return ' ';}
      ]]]

themes.yaml

  progress-bar-color: '#e5a00d'
  progress-bar-background-color: rgba(0,0,0,0.33)
  progress-bar-height: 2%

ui-lovelace.yaml

                  - type: conditional
                    conditions:
                      - entity: select.conditional_media
                        state: Shield TV
                    card:
                      type: custom:button-card
                      entity: media_player.shield_tv_plex
                      triggers_update: sensor.youtube_watching
                      template:
                        - conditional_media
                        - icon_shield_tv
                        - progress_bar