Make a contact phone number a mandatory field at the checkout.

Currently, if a new custom field is added to a product, a user cannot add a response to the new custom field for subscriptions to that product that were created before the custom field was added.

Change this to allow the user to add a response for the new field. This is useful for users who want to begin using custom fields to synchronise IDs between their internal systems.

Add the ability to remove user created custom fields from the [Companyname]'s custom fields menu

Ability to set limitations on custom field inputs for checkout. Limitations should be customizable, e.g. number only, car registraton plates, no spaces or special characters, 5 digits only, etc.

Once a custom field with the dropdown field type is created, the user is unable to delete or edit the dropdown options that they have already added. Add the ability to delete the dropdown options like you can when creating the custom field. This means that the user doesn't have to create the field all over again.