In my opinion if you are doing SEO well you will be spending a lot of time on your website, fine tuning content and content tags, adding new content, deleting old content and so on. You will also have a sitemap (won't you) that needs updating.
If doing all these things on your site is a fraught exercise you are making your SEO harder than it needs to be or worse, you are not doing your SEO because it's such pain in the arse.
Using a good Content Management System will allow you to manage your site and carry out your SEO in a pain free way. There are many very capable systems out there both free and commercial. Our tool of choice is a mature Open Source system that makes running a well SEO'd site a breeze.
Go on, take the line of least resistance, you know you want to.