Naturalization-renounce nationality

I had my final interview on March 2021 and from now I have to wait for the result which might come within 6 months or longer.
Meanwhile, I am thinking about renouncing (losing) my current nationality after the positive result. I do not have any problem renouncing my current nationality and technically it is possible in my country but because of corrupted and unstable government, this process can take years in my country. And I have heard that Japanese nationality will not be granted until I renounce the first nationality.
What can I do in this case? Is it possible to provide evidence and supporting documents to express this problem and be exempt from the process?
Does the assistance of a lawyer help?
What was your experience of renouncing your nationality to get Japanese nationality?
Any similar experience in here?
Thank you in advance for your comments.

You can't re announce your nationality, unless Nautrilization certificate issued to you, I know it's quite a old post, were you Nautrilization approved? Or you are still waiting?