Yes! It’s a bit of an open question still in Solid, we have https://github.com/solid/solid-panes/blob/master/Documentation/conventions.md which I plan to move under https://github.com/pdsinterop so that it hopefully we can somehow achieve interoperability between Solid, remoteStorage, and Nextcloud. We received some funding from NGI-Zero:PET and I also applied for NGI-Pointer funding which would help me to work more on this in the coming year.
I’ll look into your geo-location example and compare it to https://www.eventbrite.com/e/solid-world-june-tickets-104631158612# as well. Basically what Sharon did with https://github.com/SharonStrats/find-my-friends was to share location at 3 levels of precision, and you can choose which level is publically viewable (e.g. a 100km x 100km box), and then your closer friends see a more precise location (e.g. a 100m x 100m box).