How does the application work at a high level, what rights does the family member receive, how long does the status last, and how can it become independent or longer-term where officially stated?
The application is made on Form 18 and submitted by the applicant in person. A permanent residence permit holder has all the rights, privileges, duties and obligations of a citizen, save those a law or the Constitution explicitly ascribes to citizenship. The Act provides that it lapses if the holder does not apply for its confirmation within two years of turning 18.
See recorded sources
Limits of the record- The captured sources do not describe the confirmation procedure after age 18.