Important to involve an immigration lawyer for change of residence status?

I've been living in Japan for 10 years, and my residence status renewals have all been handled by my employer so far. I got married a few years ago, and have decided to switch to "Spouse of Japanese National" - since this is a personal change, my employer said their lawyer would not be involved.

I've completed the forms which didn't seem overly difficult, and neither I nor my spouse have ever had any financial, legal, or employment issues - that said, would it still be helpful to involve a third-party immigration lawyer to check the documents and make sure everything is in order?