No matter what change you are planning to make to your website, be it big or small, you should always apply The Jurassic Park Test.
That's our shorthand for making sure that the change we are making to a client website has a metric behind it that we can use to let us know if the change was effective or not.
For example, if you're making a change because you think it will improve your SEO shouldn't you take a measure of how good your SEO is now? You may choose to take a snapshot of your organic traffic, you may choose to track your average position or click-through rate in Google Search Console. You may decide that all of these metrics are important. The most important thing, however, is make sure that you have a metric and you measure the metric before you make the change.
If you can't pin your change down to a metric then you've got a tough question to answer - should you make this change at all.
Never lose sight of what your website is for and how you measure it.