Hi CJ,
I can't imagine a situation where I'd want to do this, but I'm sure you've done the analysis to determine that it's better for your UX. Just make sure you consider this:
Not sure what you're using to make the nav dynamic, but you should make sure Google sees it the way you intend. You can use the Fetch and Render in Search Console. You can also use the first part of this inforgraphic to set up a browser to view your site in a live environment the way search engines see your site.
You'll want to make sure that once you've disabled CSS and JS that your navigation is still visible. A lot of authority/juice/whateveryouwantocallit is passed through your nav. Having your nav visible this way also ensures quicker crawling/indexing of new content on your site.
Being notified of issues like this gives you items to take action on and improve your overall site visibility.