Up-to-date standards are offered for checking compliance, and it provides a cost-effective way to scan a site for compliance. There's services out there where it'd cost more than $150 (the current cost of a 1 site 1 year license) for the size of the sites I'm working with. I'm very happy to see this offering in the first place, and it's even nicer to see how thorough it looks to be. Of course, it's not perfect so I'd love to see more of the WP.org listing fleshed out (the developer author/contributor mention is missing, etc.), I'd love to see the free version on GitHub (or similar for community development assistance [I have a few things I'd help with] which is very nice to see in a WP.org listing to show there's support / ongoing development for the plugin), and of course I'd love to see the server-side checker come to feature-parity with WAVE (currently WAVE is showing a few things the server-side checker doesn't have [color contrast, etc.]) Keep up the great work!
Use the plugin, follow its instruction, and resolve the compliance issues identified. You’ll find that using the plugin will save you an incredible amount of time as you maintain your site’s compliance on a month-to-month basis. The best part, it identifies the compliance issues and tells you exactly which code elements are out of compliance and why! Our average customer is reporting a 10x-20x time savings over manually identifying and fixing these problems. In extreme cases more than 30x time savings has been reported! Using the plugin alone does not guarantee compliance. Some parts of accessibility can’t be automatically scanned and must be manually audited but we also provide independent 3rd-party audits and certifications of compliance. The Accessibility Suite Pro Plugin for WordPress makes this process profoundly easier.