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
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