There’s indeed no “proper” way of showing 3D audio codec information in skins atm. The infolabel available for audio codec information is limited to 2D audio codecs - AFAIK this won’t change with Leia (team Kodi has not announced any change to the respective infolabel yet).
There’s only one way to show 3D audio information with our OSMC skin currently - which is file naming. I’ve put together a longer explanation for another user a while back which should provide all the information: The OSMC Skin
If there’s anything else, don’t hesitate to ask 