If you are a programmer, then the Roon API https://github.com/RoonLabs/node-roon-api and specifically the Roon Transport API https://github.com/RoonLabs/node-roon-api-transport provide access to displayable now playing information as well as transport control (play/pause, fwd, rev, seek etc). There are other APIs for library browsing as well.
This Transport API is not a metadata API as such as the resulting text is provided in three display formats - one line, two lines and three lines (all of which are untagged) along with a URL and API to access artwork (via the Roon image API https://github.com/roonlabs/node-roon-api-image).
The Roon API provides basic examples to get you going and is I think very straight forward for a programmer.
As for using the Roon display, you may get better behaviour using an up to date browser such as Chrome or Safari. The Roon display will show information that the APIs I mention above provide as it uses them (and others) and do the Roon extensions that provide web UIs for now playing information and basic transport control.