I am about to sign a contract with the university that I'm currently studying in as a research assistant (HiWi). It seems that since the hours and salaries are below a legal standard, I am not required to make compulsory contribution to Rentenversicherung. The secretary asked me whether I want make a 3.9% voluntary contribution to the Rentenversicherung. She explained to me that this would add certain "points" to my Rentenversicherung account, which would be relevant to the amount of money I get after retirement, if I still remain in the German Rentenversicherung system by that time, of course.
However, she said it might not make that much sense since the current salary is low and the points contributed would be minimum. In the end, she asked me to come back next week with my decision, after I've done more research on the topic.
The actual contribution might seem indeed minimum, since I only get several hundred Euros of payment each month anyways. However, AFAIK, in the legal documents that I've read about German residence and nationality, contribution to the pension scheme is regarded as an important/mandatory factor to consider regarding one's permanent residency or naturalization application. For example, in section 18b, item 3 of Residence Act, it is stated that:
he or she has paid compulsory or voluntary contributions into the statutory pension scheme for at least 24 months or furnishes evidence of an entitlement to comparable benefits from an insurance or pension scheme or from an insurance company
I'm currently keeping permanent residency as a viable future option to consider after my graduation. In this case, would paying voluntary contribution to the pension scheme count towards these 24 months, and potentially help my future applications in these aspects? Or, is it the case that since the amount is too little and that I'm still a student, it would be of no use? I'm quite confused at the moment.