How to alter storageSettingsForm in a custom Field Type definition, set default cardinality and not allow change Trying to set Allowed number of values always to be 1 and not allowing multiple values for a custom Drupal 8 field. 
How to do that?
Do I need a form_ID_alter or a storageSettingsForm/defaultStorageSettings implementation?

I see this field is not included in the storageSettingsForm $form or parent::defaultStorageSettings()

Not sure if the best way is to set it as configuration or alter the form.
Is there an annotation for this or something?
Any example module that does this?

Thanks
Problem solved in 8.4.0 :) 

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