Our client's Magento website has been running for at least a decade, so has a lot of old legacy categories for Brands they no longer carry.

We're looking to trim down the amount of unnecessary URL Redirects in Magento, so my question is:

Is there a way that is SEO efficient to setup permanent redirects at a server level (nginx) that Google will crawl to allow us at some point to delete the categories and Magento URL Redirects?

If this is a good practice can you at some point then delete the server redirects as google has marked them as permanent?