In case anyone is still monitoring this thread …
I just developed a new SoundTouchPlus custom component if you’re interested. It can easily be installed via HACS as well. More information can be found in this forum post.
It can play HTTPS media streams. Example:
service: media_player.play_media
data:
media_content_type: music
media_content_id: >-
https://stream.radioparadise.com/aac-128
target:
entity_id: media_player.soundtouch_10