My request at this point is if the developers of the plugin could please implement a solution like this so that the plugin can be compliant natively, without me having to jump in and edit the code every time the plugin is updated. It doesn’t need to be this solution exactly, as this is admittedly a bit of a rough fix, but if the buttons could be modified with ADA compliance in mind, it would make things a lot easier for sites that use this and have these requirements to meet.

The Department of Justice’s revised regulations for Titles II and III of the Americans with Disabilities Act of 1990 (ADA) were published in the Federal Register on September 15, 2010. These regulations adopted revised, enforceable accessibility standards called the 2010 ADA Standards for Accessible Design, "2010 Standards." On March 15, 2012, compliance with the 2010 Standards was required for new construction and alterations under Titles II and III. March 15, 2012, is also the compliance date for using the 2010 Standards for program accessibility and barrier removal.

Complying with ADA provisions will cost you time, money, and human effort. Based on the audit results, you will know accurately the amount of time, human effort, and money you need to invest in compliance. Armed with these facts, you can start budgeting for the above three forms of cost—time, money, and human effort. This will require a clear roadmap.

Luckily, the international nonprofit World Wide Web Consortium (W3C) brings together smart people who develop open standards to ensure the long-term growth of the Web. They produce recommendations for making websites fair and equally accessible for the highest number of people possible. Their Web Content Accessibility Guidelines (WCAG) 2.1 offer clear guidance for web developers to achieve ADA compliance. 

We not only referenced the ADA’s requirements while building the website, but also sat down one-on-one with users who are blind to see how they navigated the site. These individual sessions were invaluable and provided more insights than just the law’s basic requirements. Instead of making assumptions about how these users would interact with the site, we took the time to observe their real interactions and used that data to formulate new features.
For people who are deaf, have hearing loss, or are deaf-blind, this includes providing a qualified notetaker; a qualified sign language interpreter, oral interpreter, cued-speech interpreter, or tactile interpreter; real-time captioning; written materials; or a printed script of a stock speech (such as given on a museum or historic house tour). A “qualified” interpreter means someone who is able to interpret effectively, accurately, and impartially, both receptively (i.e., understanding what the person with the disability is saying) and expressively (i.e., having the skill needed to convey information back to that person) using any necessary specialized vocabulary.
Attitudes toward digital accessibility have evolved over time. In 2010, the Justice Dept. said they would address the topic. They said the ADA covers web sites, including companies that don’t have brick and mortar presences. They said companies can comply with the law by offering an alternative means of access, so if a web site isn’t ADA compliant, they could offer 24/7 phone access as an example of alternative access.
Level AA is a little more significant, and makes sites accessible to people with a wider range of disabilities, including the most common barriers to use. It won't impact the look and feel of the site as much as Level AAA compliance, though it does include guidance on color contrast and error identification. Most businesses should be aiming for Level AA conformity, and it appears to reflect the level of accessibility the DOJ expects. 

Penn in particular nearly made the cut because I really like their keyboard accessibility. It amazes me how few sites provide visible indication of keyboard focus, when it's incredibly simple to achieve (just add a style for a:focus in your style sheet). Penn did this, and consequently it's very easy for sighted keyboard users to keep track of their position as they tab through the page. They also included a keyboard-accessible dropdown menu. However, there are some dynamic features on the Penn home page that really need ARIA markup for full accessibility. They also have a few contrast problems, most notably their slideshow navigation, which is red-on-red:
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.
Thanks for writing. While I’m not a lawyer I believe if your physical practice is ADA exempt your web presence, as an extension of that physical business would maintain the same exemption status. If you’d like to be absolutely certain I’d confer with an ADA lawyer (email us, questions at yokoco dot com if you need a referral) but I don’t believe you have reason to worry.
In addition, covered entities are not required to provide any particular aid or service in those rare circumstances where it would fundamentally alter the nature of the goods or services they provide to the public. In the performing arts, for example, slowing down the action on stage in order to describe the action for patrons who are blind or have vision loss may fundamentally alter the nature of a play or dance performance.
The Federal Communications Commission (FCC) enforces regulations covering telecommunication services. Title IV of the ADA covers telephone and television access for people with hearing and speech disabilities. It requires telephone and Internet companies to provide a nationwide system of telecommunications relay services that allow people with hearing and speech disabilities to communicate over the telephone.