Currently, only the primary custom object field and association label shows up in the contact record's associations in the association tab. It would be nice to be able to check which custom fields also show up.
Our use case: B2B sales, we created a custom object for a client to be able to track serial numbers for warranty start/end date tracking. In the custom object menu, we also have a custom field where you can select the product that was purchased. In the contact record, you can only see the primary custom object field (serial number) and their association label (customer vs reseller), it would be nice if you could select 1-2 more custom field lines to also show up to give more information at a glance: IE serial number (default), product name and status.