Sorry, I guess I didn’t quite understand. So you want to create a new field type that makes use of an existing field type but just add additional options.
I could be wrong, but I think that what you’re really looking to do is “extend” one of the existing fields.
Instead of this at the top of the new field class acf_field_FIELD_NAME extends acf_field
you could extend the page link field
class acf_field_FIELD_NAME extends acf_field_page_link
Then I think you would only need to write new functions to replace parts of the page link field, like
render_field
render_field_settings
format_value
update_value
