AUTOMATIC table linking with Privacy in forms

Hi,
I know there are MANY posts on the topic but my request is a mix of them aiming to make the whole linking super simple.
We have an Airtable form on a website which populates a “Opportunities” table. One field is “email”.
We have another table in the Base which is “Contacts”, that have an “email” primary key.
We want the form to immediately link the Email that was recorded with either the existing Contact found in Contacts or create a new Contacts entry.

Automatic linking would happen if in the form the “Email” question was a “Link to another table” field type. Of course, we don’t want to do this for privacy reasons: then anyone could look up the other existing emails. Plus there doesn’t seem to be the option in such form fields to “create a new entry”, only select existing ones.

Currently, our very manual process is to add another column in the “Opportunities” table, “link to another table” type, next to the “email” field. Then go “copy-paste” each recorded email in that cell. When it matches an existing record it links to it, and otherwise this paste creates a new Contact in the Contacts table.

What we would request is that a link between tables can be created directly from a form entry. There would be the choice in the Form editor either to have a “select existing entries” OR a simple text (or email) input field that then has the exact effect of the “copy-paste” step.

You can use an Automation to do this for you. Set the trigger to run when a form is submitted, then use an Update Record step to insert the value of the email field into the link field.