Hi @quantum_leap
By using the 'form' => false option, you need to create a custom code to handle the saving process. To do that, you need to know how WP Job Manager form works and add the update_field() function to save the posted custom field to the database. I believe you can get the custom fields data from the form like this:
$custom_field_data = $_POST['acf']['field_1234567890abc']
Where ‘field_1234567890abc’ is the key of your custom field.
Regarding the warning messages, I’m afraid I’m not able to give you direction regarding that issue. Could you please ask it to WP Job Manager support?
I hope this makes sense. Thanks 🙂
