My 2 cents from being a user in stead of a developer

[joebordes]

I understand. We have used the tooltip functionality in the past to do this. As you probably know you can select fields to be shown in a small popup div of the record you are hovering over. We have added useful contextual information to that popup for some clients that need more information

Maybe we could create a business map that defines more information to show in the tooltip. Or a business map to completely override the current tooltip for some other widget more capable of holding and showing structured information

https://www.lightningdesignsystem.com/components/modals/
https://www.lightningdesignsystem.com/components/panels/
https://www.lightningdesignsystem.com/components/popovers/
https://www.lightningdesignsystem.com/components/tooltips/