I’d love to see something like this implemented - equivalent to a lookup field in Salesforce (and many other tools) - so you could create a custom reference to another object, whether it be a contact to another contact, or account to another account, or two different object types.
One use case we have at the moment: we work with partners, we want to keep track of which partners work with which prospect or customer accounts - so would be great if we had a “Partner” field on a company object that could then link to other companies (can obviously realte companies to eachother via parent and child relationships, but this would allow us to capture other relationships)