I'm afraid it won't reduce the impact, your server takes the initial load of rendering instead of the browser, and the browser takes over for each re-render.
Not sure how Next.js does it but you should probably try putting NODE_ENV=production in the "build" script in package.json like in "start"?
I had a quick glance over Next.js's docs and it looks like they should handle this automatically just by `next build`. ¯\_(ツ)_/¯