Overlay Position and Recommendations
https://www.accessibilityassociation.org/s/overlay-position-and-recommendations
アクセシビリティオーバーレイに関する、IAAP (International Association of Accessibility Professionals) の公式見解。
"in relation to Overlay technologies, at this time companies should refrain from using marketing language implying that a website or application can be made fully accessible to all people with disabilities by simply installing a plugin or widget without requiring additional steps or services."