“Under the hood”, or rather in the Blocks API, the option for Record Link fields which controls whether in the Airtable environment (data view or Interface) you can manually add multiple records is called “prefers single record link” rather than what is displayed to users in the Field Config panel as “allow linking to multiple”
The under the hood terminology is more accurate. Airtable will only stop you from adding multiple records if you are manually doing so from inside Airtable’s table, expanded record, or Interface views.
I’m not sure what Airtable’s recourse here should be. You could have a dialog warn you that x number of Link Fields won’t carry over because they have “select one” turned on, but that won’t work for records created via Automations or API.
