Do not allow ex workers to add National identifiers and date of birth

Summary

Do not allow ex workers to add National identifiers and date of birth

Content

There is a new auto enabled feature in 21C that allows ex workers that are applying to add new NI or D.O.B. 

The feature will be auto enabled however we do not want to allow people to do this as these details should not change.

Any Ideas on how we can prevent candidates doing this?

Version

21C