Going with another Discord update which has been documented a few days ago, it is now possible to enhance even more an activity presence, allowing pretty much all Spotify features.
discord/discord-api-docs#7674 added those new fields:

• status_display_type, to choose which line is shown under a user's name (instead of playing foobar2000, it could be the song's title).
• state_url and details_url for clickable links in both lines.
• assets.large_url and assets.small_url are pretty self-explanatory too.

I'm only opening this to test the water and also keep people updated here. The question can be asked though: are those new available fields relevant for our usage here on an app that's main purpose is to read files? If so, where to redirect people if they click on the links? And of course, how to build all those links if it's done automatically as it is for the cover image?

After using this component for a while I noticed some flaws as it heavily relies on MusicBrainz so consider this a side-debate that could be it's own issue if necessary. To allow for more coverage of usages, it makes sense to me to give users the choice of setting the links and image URLs themselves. With only a few more boxes in settings, one can define which file metadata to look for when building the full presence object. This way, by going through some scripts like the musicbrainz tagger component, all metadata is set for all files making the source reliable once playback is started.

As always, keep up the good work you all, I'm still in the corner if anyone wants my two cents to feed the debate!