Hey Casey, this is one of the areas where things get a little weird because the W3 doesn’t actually have any say over the ADA guidelines, it is more than the ADA guidelines adopted the WCAG 2.0 guidelines as just that, a guideline to help. As far as I know, the tool you’ve linked to hasn’t been used in any judgements I’m aware of. Usually when it comes down to making a decision on if something is/isn’t compliant they have people use the actual PAWS tools and show what elements do/don’t work as intended or are otherwise inaccessible. Hope this helps!

VERY useful. I searched for a plugin that had WAVE scanning integrated and this plugin came up. I was a bit hesitant because there were only a few reviews and the price was higher than most plugins. However, if the plugin worked, it would save me $1,000 from requesting a WAVE scan of my entire site. In short, this plugin is amazing. It is super-detailed. That makes it a bit longer to learn and master. However it makes it amazingly useful. If you take compliance seriously, this is the plugin for you. I am not a developer, but understand more about coding than the average content creator. I was able to understand this plugin, though it took several hours. Don't take that as a bad thing. It was necessary, and I learned a TON about ADA compliance in the meantime. When I had a question, the author was super-fast and helpful. I highly recommend this plugin.

Video relay service (VRS) is a free, subscriber-based service for people who use sign language and have videophones, smart phones, or computers with video communication capabilities. For outgoing calls, the subscriber contacts the VRS interpreter, who places the call and serves as an intermediary between the subscriber and a person who uses a standard voice telephone. The interpreter tells the telephone user what the subscriber is signing and signs to the subscriber what the telephone user is saying.
The guidelines are broken down by four main principles: perceivable, operable, understandable, and robust. Under each principle, there are guidelines that provide specific goals a website should work toward. Under each guideline, there are testable success criteria. Those criteria are graded A, AA, or AAA. This grade shows the level of conformity to accessibility, AAA being the highest. The law only requires A and AA guidelines to be met.