I think it would be great if ACF didn’t add custom fields for null values. Even on posts with no ACF fields selected, custom fields are still created. This creates a lot of useless custom fields with “null” values.
This is particularly a problem when the existence of a custom field is used for determining “null.” For instance, consider a custom field “Name” with a value of “null.” Well, is there a name? Is the name null? This wouldn’t be an issue if the custom field wasn’t created.
I’m using the select field with “allow null” set to yes. With the select box left on “- Select -” it still saves a value of “null” to the custom field. This leads to a bunch of custom fields like this:
It appears this just isn’t with null values, as ACF creates blank custom fields also (see the “link” custom field above).