The manual methods can be risky and complicated due to the repetitive steps.
Plus, there is no guarantee that this method will provide you with 100% satisfactory results.
In this situation, it is advised to opt for a third-party professional solution.
After searching continuously on the internet, I have come across the perfect solution; NSF to PST Converter.
This utility helps users to export emails, contacts, calendars, tasks, and journals from the NSF files. With that being said, it also preserves internet header and HTML formatting as well as Doc Links.

Get detailed info - https://www.systoolsgroup.com/import/nsf-files-to-outlook/