Google’s bots crawl your site to determine its quality, and correct technical on page optimization is one of the main signals used. When you optimize your page based on the recommendations of the website analyzer, you can increase your organic traffic, improve ranking positions, and stay competitive against other sites ranking for your target keywords.
Brian, I’m going through Step 3, which is referring to the one version of the website. I found a very good free tool (https://varvy.com/tools/redirects/) to recommend. It checks on the redirect and gives you a visual number of hops. More hops mean more delay. For example, if I use your manual method to check on https://uprenew.com, all looks good. However, if I use the tool and check, I realize there is an unnecessary 1 hop/delay, whereby I can fix it. Hope this helps. : )
The audit is for all pages and not only one. What happens in the majority of the cases is that pages / posts have similarities so you can group them together. For example the pages of a website may be ok but the blog post pages may be missing titles. It’s a lot of work especially for a 500 pages website but you can start from the most important pages first and work your way to the rest