Ok, that makes sense.
First of all, I would avoid using user specific columns in your favorites table. It’s not necessary and will just be a headache to deal with. It should just be a normal basic column to store the unique number. Also add an email column to store the signed in user’s email when you add the row. You can apply row owners to that email column or filter by that email column.
Make sure your relation is a single relation and uses that new non user specific unique number column. I think what I would do then is create maybe 3 or 4 lookup columns in your Favorites table that use the relation and return the important details you need to fill in the list details, such as heading, description, meta, etc.
Then on your favorites list, change the action to Show Details → Relation instead of This Item. That way the favorites list will directly open the related main table details when you click on an item, instead of opening the details screen for the favorites table.